共用题干B1i'k Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space. Scientists have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force, hydrogen ends up putting pressure onto the star' s surface until it suddenly explodes then collapses.2 Black holes come from stars that are made of hydrogen,other gases and a few metals. When these explode it can turn into a stellar-mass ( 恒星质量）black hole , which can only occur if the star is large enough (should be bigger than the sun) for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle. Try to see and compare:if a star that' s ten times the size of the sun endsup being a black hole that' s no longer than 70 kilometers ,then the Earth would become a black hole that' sonly"fraction of an inch! 3 Objects that get sucked in a black hie will always remain there,never to brsak fren. But rememberthat black holes can only gobble up（吞噬）objects within a specific distance to it It' s possible for a largestar near the sun to become a black hole,but the sun will continue to stay in place. Orbits (轨道）do notchange because the newly formed black hole, contains exactly the same amount of mass as when it was a star,only this time its mass is totally contracted that it can end up as on biggeer tnan a state. 4 So far, astronomers have figured out that black holes exist because of Albert Einstenin's theory of relativity. In the end,through numerous studies ,they have discovered that black holes truly exist. Since blackholes trap light and do not give off light,it is nearly impossible to detect black goles via a telescope. Butastronomers continue to study galaxies (银河系）,space and the solar system to understand how black holes misht evolve. It is possible that black holes can exist for millions of years,and later contribute to a biggerprocess in galaxies ,which can eventually lead to creation of new entities（实体）.Scientists also credit blackholes as helpful in learning how galaxies began to form. A newly formed black hole and the star it comes from are of____________.A: the existence of black holesB: the creation of new entitiesC: the same amount of massD: an explosion of huge starsE: a fraction of an inchF: the tiniest narticle
共用题干
B1i'k Holes
1 Black holes can be best described as a sort of vacuum,sucking up everything in space. Scientists
have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer
burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,
hydrogen ends up putting pressure onto the star' s surface until it suddenly explodes then collapses.
2 Black holes come from stars that are made of hydrogen,other gases and a few metals. When these
explode it can turn into a stellar-mass ( 恒星质量）black hole , which can only occur if the star is large enough
(should be bigger than the sun) for the explosion to break it into pieces,and the gravity starts to compact
every piece into the tiniest particle. Try to see and compare:if a star that' s ten times the size of the sun ends
up being a black hole that' s no longer than 70 kilometers ,then the Earth would become a black hole that' s
only"fraction of an inch!
3 Objects that get sucked in a black hie will always remain there,never to brsak fren. But remember
that black holes can only gobble up（吞噬）objects within a specific distance to it It' s possible for a large
star near the sun to become a black hole,but the sun will continue to stay in place. Orbits (轨道）do not
change because the newly formed black hole, contains exactly the same amount of mass as when it was a star,
only this time its mass is totally contracted that it can end up as on biggeer tnan a state.
4 So far, astronomers have figured out that black holes exist because of Albert Einstenin's theory of
relativity. In the end,through numerous studies ,they have discovered that black holes truly exist. Since black
holes trap light and do not give off light,it is nearly impossible to detect black goles via a telescope. But
astronomers continue to study galaxies (银河系）,space and the solar system to understand how black holes
misht evolve. It is possible that black holes can exist for millions of years,and later contribute to a bigger
process in galaxies ,which can eventually lead to creation of new entities（实体）.Scientists also credit black
holes as helpful in learning how galaxies began to form.
B1i'k Holes
1 Black holes can be best described as a sort of vacuum,sucking up everything in space. Scientists
have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer
burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,
hydrogen ends up putting pressure onto the star' s surface until it suddenly explodes then collapses.
2 Black holes come from stars that are made of hydrogen,other gases and a few metals. When these
explode it can turn into a stellar-mass ( 恒星质量）black hole , which can only occur if the star is large enough
(should be bigger than the sun) for the explosion to break it into pieces,and the gravity starts to compact
every piece into the tiniest particle. Try to see and compare:if a star that' s ten times the size of the sun ends
up being a black hole that' s no longer than 70 kilometers ,then the Earth would become a black hole that' s
only"fraction of an inch!
3 Objects that get sucked in a black hie will always remain there,never to brsak fren. But remember
that black holes can only gobble up（吞噬）objects within a specific distance to it It' s possible for a large
star near the sun to become a black hole,but the sun will continue to stay in place. Orbits (轨道）do not
change because the newly formed black hole, contains exactly the same amount of mass as when it was a star,
only this time its mass is totally contracted that it can end up as on biggeer tnan a state.
4 So far, astronomers have figured out that black holes exist because of Albert Einstenin's theory of
relativity. In the end,through numerous studies ,they have discovered that black holes truly exist. Since black
holes trap light and do not give off light,it is nearly impossible to detect black goles via a telescope. But
astronomers continue to study galaxies (银河系）,space and the solar system to understand how black holes
misht evolve. It is possible that black holes can exist for millions of years,and later contribute to a bigger
process in galaxies ,which can eventually lead to creation of new entities（实体）.Scientists also credit black
holes as helpful in learning how galaxies began to form.
A newly formed black hole and the star it comes from are of____________.
A: the existence of black holes
B: the creation of new entities
C: the same amount of mass
D: an explosion of huge stars
E: a fraction of an inch
F: the tiniest narticle
A: the existence of black holes
B: the creation of new entities
C: the same amount of mass
D: an explosion of huge stars
E: a fraction of an inch
F: the tiniest narticle
参考解析
解析：第一段描述了什么是黑洞，以及它产生的缘由―巨型恒星爆炸，并叙述了恒星爆炸的 原因和简要过程。再看选项，只有F项符合题意。
第二段的主要内容是：恒星来自由氢气、其他气体和一些金属组成的恒星；当这些物质 爆炸时，恒星就变成了质量与原先的恒星等同的黑洞，恒星的每个碎片都被重力压缩成极小的 颗粒。观察选项，似乎E、F两项都可选，但一则上一小题只能选F项，二则此段虽也讲了黑洞 是怎么形成的，但比较侧重黑洞形成过程中，原来的恒星变成极小的颗粒。由第三段最后一句 也可知，这些颗粒的质量总和与原来的恒星一样，正是这些颗粒使黑洞有极大的吸附性，而成 其为“黑洞”。因此，黑洞就是由这些极小却质量巨大、吸附性极强的颗粒构成的。故选E。
第三段描述了黑洞极大的吸附性，及其具有如此大的吸附性的原因。黑洞形成后，周 围一定距离内的几乎一切东西都会被吞噬而难以逃脱，故选A。
第四段主要讲黑洞存在的依据及科学家们的研究和设想。故选B。
由第一段第二句“…black holes come from an explosion of huge stars.”可知答案。
由第二段第二句后半部分“…the gravity。tartst。。ompact evey piece into the tiniest particle”可知答案。
由第三段最后一句“…the newly formed black hol。Contains。xactly the same amount of mass as when it was a star…”可知答案。
由第四段第一句话可知答案。第4部分：阅读理解第一篇 本文主要讲的是科学家利用植物的光合作用使其生产氢气等可供人类使用的能源。
第二段的主要内容是：恒星来自由氢气、其他气体和一些金属组成的恒星；当这些物质 爆炸时，恒星就变成了质量与原先的恒星等同的黑洞，恒星的每个碎片都被重力压缩成极小的 颗粒。观察选项，似乎E、F两项都可选，但一则上一小题只能选F项，二则此段虽也讲了黑洞 是怎么形成的，但比较侧重黑洞形成过程中，原来的恒星变成极小的颗粒。由第三段最后一句 也可知，这些颗粒的质量总和与原来的恒星一样，正是这些颗粒使黑洞有极大的吸附性，而成 其为“黑洞”。因此，黑洞就是由这些极小却质量巨大、吸附性极强的颗粒构成的。故选E。
第三段描述了黑洞极大的吸附性，及其具有如此大的吸附性的原因。黑洞形成后，周 围一定距离内的几乎一切东西都会被吞噬而难以逃脱，故选A。
第四段主要讲黑洞存在的依据及科学家们的研究和设想。故选B。
由第一段第二句“…black holes come from an explosion of huge stars.”可知答案。
由第二段第二句后半部分“…the gravity。tartst。。ompact evey piece into the tiniest particle”可知答案。
由第三段最后一句“…the newly formed black hol。Contains。xactly the same amount of mass as when it was a star…”可知答案。
由第四段第一句话可知答案。第4部分：阅读理解第一篇 本文主要讲的是科学家利用植物的光合作用使其生产氢气等可供人类使用的能源。
相关考题：
Why is Franklin described as “Dark Lady of DNA”?A. She developed pictures in dark labs.B. She discovered the black X------ the shape of DNA.C. Her name was forgotten after her death.D. Her contribution was unknown to the public.
The most ______evidence of black holes comes from research into binary star systems.A. convincingB. convinceC. convincedD. convinces
According to the passage which of the following is true?[A] A fixed star refers a star that is always stationary on the sky.[B] Scientists can tell the motion of the earth from the motions of other five planets.[C] Ancient people had scanty knowledge about the movement of the stars.[D] All the stars on the sky can be seen all the year around.
There might be a massive black hole at the center of our galaxy______(swallow)up stars at a very rapid rate.
Sudden unloading of a diesel engine can cause ______．A.Decreased fuel efficiencyB.Increased exhaust temperatureC.Black smokeD.Overspeed trip
共用题干B1i'k Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space. Scientists have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force, hydrogen ends up putting pressure onto the star' s surface until it suddenly explodes then collapses.2 Black holes come from stars that are made of hydrogen,other gases and a few metals. When these explode it can turn into a stellar-mass ( 恒星质量）black hole , which can only occur if the star is large enough (should be bigger than the sun) for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle. Try to see and compare:if a star that' s ten times the size of the sun endsup being a black hole that' s no longer than 70 kilometers ,then the Earth would become a black hole that' sonly"fraction of an inch! 3 Objects that get sucked in a black hie will always remain there,never to brsak fren. But rememberthat black holes can only gobble up（吞噬）objects within a specific distance to it It' s possible for a largestar near the sun to become a black hole,but the sun will continue to stay in place. Orbits (轨道）do notchange because the newly formed black hole, contains exactly the same amount of mass as when it was a star,only this time its mass is totally contracted that it can end up as on biggeer tnan a state. 4 So far, astronomers have figured out that black holes exist because of Albert Einstenin's theory of relativity. In the end,through numerous studies ,they have discovered that black holes truly exist. Since blackholes trap light and do not give off light,it is nearly impossible to detect black goles via a telescope. Butastronomers continue to study galaxies (银河系）,space and the solar system to understand how black holes misht evolve. It is possible that black holes can exist for millions of years,and later contribute to a biggerprocess in galaxies ,which can eventually lead to creation of new entities（实体）.Scientists also credit blackholes as helpful in learning how galaxies began to form. Paragraph 2_____________A:What Happens to the Objects Around a Black Hole?B:Is There Proof That Black Holes Really Exist? C:How Were Black Holes Named? D:What Are Different Types of Black Holes?E:What Are Black Holes Made of?F:How Are Black Holes Formed?
共用题干B1i'k Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space. Scientists have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force, hydrogen ends up putting pressure onto the star' s surface until it suddenly explodes then collapses.2 Black holes come from stars that are made of hydrogen,other gases and a few metals. When these explode it can turn into a stellar-mass ( 恒星质量）black hole , which can only occur if the star is large enough (should be bigger than the sun) for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle. Try to see and compare:if a star that' s ten times the size of the sun endsup being a black hole that' s no longer than 70 kilometers ,then the Earth would become a black hole that' sonly"fraction of an inch! 3 Objects that get sucked in a black hie will always remain there,never to brsak fren. But rememberthat black holes can only gobble up（吞噬）objects within a specific distance to it It' s possible for a largestar near the sun to become a black hole,but the sun will continue to stay in place. Orbits (轨道）do notchange because the newly formed black hole, contains exactly the same amount of mass as when it was a star,only this time its mass is totally contracted that it can end up as on biggeer tnan a state. 4 So far, astronomers have figured out that black holes exist because of Albert Einstenin's theory of relativity. In the end,through numerous studies ,they have discovered that black holes truly exist. Since blackholes trap light and do not give off light,it is nearly impossible to detect black goles via a telescope. Butastronomers continue to study galaxies (银河系）,space and the solar system to understand how black holes misht evolve. It is possible that black holes can exist for millions of years,and later contribute to a biggerprocess in galaxies ,which can eventually lead to creation of new entities（实体）.Scientists also credit blackholes as helpful in learning how galaxies began to form. Black holes are formed after_____________. A: the existence of black holesB: the creation of new entitiesC: the same amount of massD: an explosion of huge starsE: a fraction of an inchF: the tiniest narticle
The Theory of Everyone If Stephen Hawking lives until the year 2017, he will have lived more than 50 years longer than his doctors expected. When he was a college student, doctors discovered that he had a rare disease. This disease causes a gradual disintegration(分解)of the nerve cells in the brain cells that regulate voluntary muscle activity. Death almost always occurs within two or three years. Today Stephen Hawking cannot walk or speak. He cannot move his arms or his head. He cannot taste or smell anything. And yet this man is Professor of Mathematics at Cambridge University, a position held by the famous scientist Isaac Newton in 1669. Hawking is often described as the greatest scientist since Albert Einstein, but to the world outside science, he is also known as the man who made scientific theory understandable. His book, A Brief History of Time, has sold over eight million copies. He says that since he does not have to think about his body or do any of the things other men have to worry about, such as washing the car or working in the yard, he can dedicate all of his time to thinking. This puts him in the perfect position to find the answer to the question that he has dedicated his life to. His question is: Is there a complete theory of the universe and everything in it? Despite his tremendous physical disabilities, he has already made some very important discoveries about the origin of the universe, how the universe holds together, and how it will probably end. He has also been able to explain the secrets of “black holes” in space. Now he is looking for a set of rules that everything in our universe must obey. He calls it the Theory of Everything. He thinks that someone will have found the answer within the next 20 years. If Stephen Hawking is able to find his Theory of Everything, he will have given the world the opportunity to understand things that will change the whole nature of science and probably also the way we live.文章(16~22)Stephen Hawking will be 50 years old by 2017.A.RightB.WrongC.Not mentioned
共用题干B1i'k Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space. Scientists have discovered that black holes come from an explosion of huge stars. Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force, hydrogen ends up putting pressure onto the star' s surface until it suddenly explodes then collapses.2 Black holes come from stars that are made of hydrogen,other gases and a few metals. When these explode it can turn into a stellar-mass ( 恒星质量）black hole , which can only occur if the star is large enough (should be bigger than the sun) for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle. Try to see and compare:if a star that' s ten times the size of the sun endsup being a black hole that' s no longer than 70 kilometers ,then the Earth would become a black hole that' sonly"fraction of an inch! 3 Objects that get sucked in a black hie will always remain there,never to brsak fren. But rememberthat black holes can only gobble up（吞噬）objects within a specific distance to it It' s possible for a largestar near the sun to become a black hole,but the sun will continue to stay in place. Orbits (轨道）do notchange because the newly formed black hole, contains exactly the same amount of mass as when it was a star,only this time its mass is totally contracted that it can end up as on biggeer tnan a state. 4 So far, astronomers have figured out that black holes exist because of Albert Einstenin's theory of relativity. In the end,through numerous studies ,they have discovered that black holes truly exist. Since blackholes trap light and do not give off light,it is nearly impossible to detect black goles via a telescope. Butastronomers continue to study galaxies (银河系）,space and the solar system to understand how black holes misht evolve. It is possible that black holes can exist for millions of years,and later contribute to a biggerprocess in galaxies ,which can eventually lead to creation of new entities（实体）.Scientists also credit blackholes as helpful in learning how galaxies began to form. Albert Einstein's theory of relativity helps to prove____________.A: the existence of black holesB: the creation of new entitiesC: the same amount of massD: an explosion of huge starsE: a fraction of an inchF: the tiniest narticle
共用题干The DeathModern scientists divide the process of dying into two stages一(46)________.Clinical death occurs when the vital organs,such as the heart or lungs,have ceased to function,but have not suffered permanent damage. The organism can still be revived（复活）.Biological death occurs when changes in the organism lead to the disintegration（解体）of vital cells and tissues. Death is then irreversible and final.Scientists have been seeking a way to prolong the period of clinical death so that(47) ________.The best method developed so far involves cooling of the organism,combined with narcotic（麻醉的）sleep. By slowing down the body's metabolism（新陈代谢）,cooling delays the processes leading to biological death.To illustrate how this works,scientists performed an experiment on a six-year-old female monkey called Keta.(48)_________.Then they surrounded her body with ice-bags and began checking her body temperature.When it had dropped to 28 degrees the scientists began draining blood from its body.The monkey's blood pressure decreased and an hour later both the heart and breathing stopped,clinical death set in.For twenty minutes Keta remained in this state.Her temperature dropped to 22 degrees.At this point the scientists pumped blood into its body in the direction of the heart and started artificial breathing.(49)_______.After fifteen minutes,spontaneous breathing began,and after four hours Keta opened her eyes and lifted her head.After six hours,when the scientists tried to give her a penicillin injection,Keta seized the syringe and ran with it around the room.(50)__________.________（50）A:the organism can be revived before biological death occursB:clinical or temporary death and biological deathC:After two minutes the monkey's heart became active once moreD:Her behavior differed little from that of a healthy animalE:The scientists put Keta to sleep with a narcoticF:Clinical death process should be prolonged
共用题干Black Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space.Scientists have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,hydrogen ends up putting pressure onto the star's surface until it suddenly explodes then collapses.2 Black holes come from stars ihat are made of hydrogen,other gases and a few metals.When these explode it can turn into a stellar-mass（恒星质量) black hole , which can only occur if the star is large enough (should be bigger than the sun)for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle.Try to see and compare:if a star that's ten times the size of the sun ends up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that'S only a fraction of an inch!3 Objects that get sucked in a black hole will always remain there,never to break free.i1it remember that black holes can only gobble up（吞噬）objects within a specific distance to it.It's possible for a large star near the sun to become a black hole,but the sun will continue to stay in place.Orbits（轨道）do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star, only this time its mass is totally contracted that it can end up as no bigger than a state.4 Sofar,astronomers have figured out that black holes exist because of Albert Einstcin's theory of relativity.In the end,through numerous studies,they have discovered that black holes truly exist.Since black holes trap light and do not give off light,it is nearly impossible to detect black holes via a telescope.But astronomers continue to study galaxies（银河系）, space and the solar system to understand how black holes might evolve.It is possible that black holes can exist for millions of years,and later contribute to a bigger process in galaxies,which can eventually lead to creation of new entities（实体）.Scientists also credit black holes as helpful in learning how galaxies began to form.When a large star explodes,the gravity compacts every piece into______.A:the existence of black holesB:the creation of new entitiesC:the same amount of massD:an fraction of an inchE:a fraction of an inchF:the tiniest particle
共用题干Black Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space.Scientists have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,hydrogen ends up putting pressure onto the star's surface until it suddenly explodes then collapses.2 Black holes come from stars ihat are made of hydrogen,other gases and a few metals.When these explode it can turn into a stellar-mass（恒星质量) black hole , which can only occur if the star is large enough (should be bigger than the sun)for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle.Try to see and compare:if a star that's ten times the size of the sun ends up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that'S only a fraction of an inch!3 Objects that get sucked in a black hole will always remain there,never to break free.i1it remember that black holes can only gobble up（吞噬）objects within a specific distance to it.It's possible for a large star near the sun to become a black hole,but the sun will continue to stay in place.Orbits（轨道）do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star, only this time its mass is totally contracted that it can end up as no bigger than a state.4 Sofar,astronomers have figured out that black holes exist because of Albert Einstcin's theory of relativity.In the end,through numerous studies,they have discovered that black holes truly exist.Since black holes trap light and do not give off light,it is nearly impossible to detect black holes via a telescope.But astronomers continue to study galaxies（银河系）, space and the solar system to understand how black holes might evolve.It is possible that black holes can exist for millions of years,and later contribute to a bigger process in galaxies,which can eventually lead to creation of new entities（实体）.Scientists also credit black holes as helpful in learning how galaxies began to form.Black holes are formed after_________.A:the existence of black holesB:the creation of new entitiesC:the same amount of massD:an fraction of an inchE:a fraction of an inchF:the tiniest particle
共用题干Black Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space.Scientists have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,hydrogen ends up putting pressure onto the star's surface until it suddenly explodes then collapses.2 Black holes come from stars ihat are made of hydrogen,other gases and a few metals.When these explode it can turn into a stellar-mass（恒星质量) black hole , which can only occur if the star is large enough (should be bigger than the sun)for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle.Try to see and compare:if a star that's ten times the size of the sun ends up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that'S only a fraction of an inch!3 Objects that get sucked in a black hole will always remain there,never to break free.i1it remember that black holes can only gobble up（吞噬）objects within a specific distance to it.It's possible for a large star near the sun to become a black hole,but the sun will continue to stay in place.Orbits（轨道）do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star, only this time its mass is totally contracted that it can end up as no bigger than a state.4 Sofar,astronomers have figured out that black holes exist because of Albert Einstcin's theory of relativity.In the end,through numerous studies,they have discovered that black holes truly exist.Since black holes trap light and do not give off light,it is nearly impossible to detect black holes via a telescope.But astronomers continue to study galaxies（银河系）, space and the solar system to understand how black holes might evolve.It is possible that black holes can exist for millions of years,and later contribute to a bigger process in galaxies,which can eventually lead to creation of new entities（实体）.Scientists also credit black holes as helpful in learning how galaxies began to form.A newly formed black hole and the star it comes from are of__________.A:the existence of black holesB:the creation of new entitiesC:the same amount of massD:an fraction of an inchE:a fraction of an inchF:the tiniest particle
共用题干Black Holes1 Black holes can be best described as a sort of vacuum,sucking up everything in space.Scientists have discovered that black holes come from an explosion of huge stars.Stars that are near death can no longer burn due to loss of fuel , and because its temperature can no longer control the gravitational（重力的）force,hydrogen ends up putting pressure onto the star's surface until it suddenly explodes then collapses.2 Black holes come from stars ihat are made of hydrogen,other gases and a few metals.When these explode it can turn into a stellar-mass（恒星质量) black hole , which can only occur if the star is large enough (should be bigger than the sun)for the explosion to break it into pieces,and the gravity starts to compact every piece into the tiniest particle.Try to see and compare:if a star that's ten times the size of the sun ends up being a black hole that's no longer than 70 kilometers,then the Earth would become a black hole that'S only a fraction of an inch!3 Objects that get sucked in a black hole will always remain there,never to break free.i1it remember that black holes can only gobble up（吞噬）objects within a specific distance to it.It's possible for a large star near the sun to become a black hole,but the sun will continue to stay in place.Orbits（轨道）do not change because the newly formed black hole contains exactly the same amount of mass as when it was a star, only this time its mass is totally contracted that it can end up as no bigger than a state.4 Sofar,astronomers have figured out that black holes exist because of Albert Einstcin's theory of relativity.In the end,through numerous studies,they have discovered that black holes truly exist.Since black holes trap light and do not give off light,it is nearly impossible to detect black holes via a telescope.But astronomers continue to study galaxies（银河系）, space and the solar system to understand how black holes might evolve.It is possible that black holes can exist for millions of years,and later contribute to a bigger process in galaxies,which can eventually lead to creation of new entities（实体）.Scientists also credit black holes as helpful in learning how galaxies began to form.Paragraph 1________A:What Happens to the Objects Around a Black Hole?B:Is There Proof That Black Holes Really Exist?C:How Were Black Holes Named?D:What Are Different Types of Black Holes?E:What Are Black Holes Made of? F: How Are Black Holes Formed?
Black Holes Trigger Stars to Self-Destruct Scientists have long understood that supermassive black holes weighing millions or billions of suns can tear apart stars that come too close. The black hotels gravity pulls harder on the nearest part of the star, an imbalance that pulls the star apart over a period of minutes or hours, once it gets close enough. Scientists say this Uneven pulling is not the only hazard facing the star. The strain of these unbalanced forces can also trigger a nuclear explosion powerful enough to destroy the star from within. Matthieu Brassart and Jean-Pierre Luminet of the Observatoire de Paris in Meudon, France, carried out computer simulations of the final moments of such an unfortunate star's life,as it veered towards a supermassive black hole. When the star gets close enough, the uneven forces flatten it into a pancake shape. Some previous studies had suggested this flattening would increase the density and temperature inside the star enough to trigger intense nuclear reactions that would tear it apart. But other studies had suggested that the picture would be complicated by shock waves generated during the flattening process and that no nuclear explosion should occur. The new simulations investigated the effects of shock waves in detail,and found that even when their effects are included,the conditions favor a nuclear explosion. "There will be an explosion of the star-it will be completely destroyed," Brassart says. Although the explosion obliterates the star, it saves some of the star's matter from being devoured by the black hole. The explosion is powerful enough to hurl much of the star's matter out of the black hole's reach, he says. The devouring of stars by black holes may already have been observed, although at a much later stage. It is thought that several months after the event that rips the star apart,its matter starts swirling into the hole itself. It heats up as it does so, releasing ultraviolet light and X-rays. If stars disrupted near black holes really do explode, then they could in principle allow these events to be detected at a much earlier stage, says Jules Hatpern of Columbia University in New York, US. "It may make it possible to see the disruption of that star immediately if it gets hot enough," he says. Brassart agrees. "Perhaps it can be observed in the X-rays and gamma rays, but it's something that needs to be more studied," he says. Supernova researcher Chris Fryer of the Los Alamos National Laboratory in Los Alamos, New Mexico, US, says the deaths of these stars are difficult to simulate, and he is not sure whether the researchers have proven their case that they explode in the process.文章(36~40)Something destructive could happen to a star that gets too close to a black hole. Which of the following destructive statements is NOT mentioned in the passage?A. The black hole could tear apart the star.B. The black hole could trigger a nuclear explosion in the star.C. The black hole could dwindle its size considerably.D. The black hole could devour the star.
What will happen several months after the explosion of the star?A. The star's matter will move further away from by the black hole.B. The black hole’s matter will heat up.C. The torn star's matter will swirl into the black hole.D. The black hole's matter will release ultraviolet light and X-rays.
共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singularity.The center of a black hole would not really be a hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist,they are difficult to observe.These are the reasons.No light or anything else comes out of black holes.As a result,they are invisible to a telescope.In astronomical terms,black holes are truly tiny.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found,however,so black holes remain one of the mysteries of the universe.Black holes are part of space.A:Right B:Wrong C:Not mentioned
共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singularity.The center of a black hole would not really be a hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist,they are difficult to observe.These are the reasons.No light or anything else comes out of black holes.As a result,they are invisible to a telescope.In astronomical terms,black holes are truly tiny.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found,however,so black holes remain one of the mysteries of the universe.The Hubble Space Telescope helps scientists to understand the nature of the universe.A:Right B:Wrong C:Not mentioned
共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singularity.The center of a black hole would not really be a hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist,they are difficult to observe.These are the reasons.No light or anything else comes out of black holes.As a result,they are invisible to a telescope.In astronomical terms,black holes are truly tiny.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found,however,so black holes remain one of the mysteries of the universe.The center of a black hole is empty.A:Right B:Wrong C:Not mentioned
共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singularity.The center of a black hole would not really be a hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist,they are difficult to observe.These are the reasons.No light or anything else comes out of black holes.As a result,they are invisible to a telescope.In astronomical terms,black holes are truly tiny.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found,however,so black holes remain one of the mysteries of the universe.The sun is the heaviest star in the universe.A:Right B:Wrong C:Not mentioned
共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singularity.The center of a black hole would not really be a hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist,they are difficult to observe.These are the reasons.No light or anything else comes out of black holes.As a result,they are invisible to a telescope.In astronomical terms,black holes are truly tiny.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found,however,so black holes remain one of the mysteries of the universe.The nearest black holes are hundreds of light years away from us.A:Right B:Wrong C:Not mentioned
共用题干Black HolesMost scientists agree that black holes exist but are nearly impossible to locate.A black hole in the universe is not a solid object, like a planet, but it is shaped like a sphere（球体）. Astronomers（天文学家）think that at the center of a black hole there is a single point in space with infinite（无限的）density（稠密）.This single point is called a singularity（奇点）.If the singularity theory is correct,it means that when a massive star collapses,all the material in it disappears into the singularity.The center of a black hole would not really be a hole at all,but an infinitely dense point.Anything that crosses the black hole is pulled in by its great gravity.Although black holes do exist,they are difficult to observe.These are the reasons.No light or anything else comes out of black holes.As a result,they are invisible to a telescope.In astronomical terms,black holes are truly tiny.For example,a black hole formed by the collapse of a giant star would have an event horizon（视界）only 18 miles across.The nearest black holes would be dozens of light years away from Earth.One light year is about 6 trillion（万亿）miles. Even the most powerful telescopes could not pick out an object so small at such a great distance.In 1994 the Hubble Space Telescope provided evidence that black holes exist. There are still answers to be found,however,so black holes remain one of the mysteries of the universe.The attraction of two large stars leads to gravity.A:Right B:Wrong C:Not mentioned
单选题Black smoke coming from a boiler can be caused by （）.Alow water levelBhigh water levelCexcessively high fuel pressureDlow oil temperature
单选题Black smoke coming from a boiler can be caused by （）.Alow water levelBlow oil pressureCexcessively high fuel pressureDan improper air/fuel ratio
单选题Black smoke exhausting from an operating diesel engine can be caused by （）Afuel dribbling from leaking fuel injectorsBburning fuel with a high carbon contentCburning fuel with a high vanadium contentDburning fuel with a lower sulphur content
单选题High exhaust temperature and black smoke exhausting from an auxiliary diesel engine can be caused by （）.Aengine overloadBlow combustion temperatureCplugged fuel nozzle holesDexcessive compression pressure