共用题干Dark Forces Dominate UniverseThe earth,moon,sun and all visible stars in the sky make up less than one percent of the universe.Almost all the rest is dark matter and dark energy,unknown forces that _______(1)astronomers.Observations in recent years have changed the basic_______(2)of how the universe evolved and have indicated how little is known about the major forces and substances that_______(3)our world.Astronomers now know that luminous（发光的）matter一stars , planets and hot gas一 accounts_______(4)only about 0.4 percent of the universe.Non-luminous components , such as black holes and intergalactic（星系间的）gas,_______(5) up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about 73 percent.Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people."We_______(8)our very existence to dark matter,"said physicist PaulSteinhardt and a co-author of a review on dark matter which_______(9)not long ago in the journal Science."Dark matter dominated the structure_______(10)in the early universe," Steinhardt said."For the first few billion years dark matter contained most of the mass of the universe. You can think of ordinary matter_______(11)a froth（泡沫）of an ocean of dark matter. The dark matter clumps（结成块）and the ordinary matter falls into it. That_______(12) to the formation of the stars and galaxies（星系）."Without dark matter,"there would be virtually no structures in the universe,"The nature of dark matter is_______(13).It cannot be seen or detected directly. Astronomers know it is there because of its_______(14) on celestial（天体的）objects that can be seen and measured.But the most dominating force of all in the universe is called dark energy,a recently ________(15)power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed._________(6)A:written B:called C:identified D:seen
共用题干
Dark Forces Dominate Universe
The earth,moon,sun and all visible stars in the sky make up less than one percent of
the universe.Almost all the rest is dark matter and dark energy,unknown forces that
_______(1)astronomers.
Observations in recent years have changed the basic_______(2)of how the
universe evolved and have indicated how little is known about the major forces and
substances that_______(3)our world.
Astronomers now know that luminous（发光的）matter一stars , planets and hot gas一
accounts_______(4)only about 0.4 percent of the universe.Non-luminous
components , such as black holes and intergalactic（星系间的）gas,_______(5)
up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about
73 percent.
Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people.
"We_______(8)our very existence to dark matter,"said physicist Paul
Steinhardt and a co-author of a review on dark matter which_______(9)not long ago
in the journal Science.
"Dark matter dominated the structure_______(10)in the early universe,"
Steinhardt said."For the first few billion years dark matter contained most of the mass of the
universe. You can think of ordinary matter_______(11)a froth（泡沫）of an ocean
of dark matter. The dark matter clumps（结成块）and the ordinary matter falls into it. That
_______(12) to the formation of the stars and galaxies（星系）."
Without dark matter,"there would be virtually no structures in the universe,"
The nature of dark matter is_______(13).It cannot be seen or detected
directly. Astronomers know it is there because of its_______(14) on celestial（天体
的）objects that can be seen and measured.
But the most dominating force of all in the universe is called dark energy,a recently
________(15)power that astronomers say is causing the galaxies in the universe to
separate at a faster and faster speed.
Dark Forces Dominate Universe
The earth,moon,sun and all visible stars in the sky make up less than one percent of
the universe.Almost all the rest is dark matter and dark energy,unknown forces that
_______(1)astronomers.
Observations in recent years have changed the basic_______(2)of how the
universe evolved and have indicated how little is known about the major forces and
substances that_______(3)our world.
Astronomers now know that luminous（发光的）matter一stars , planets and hot gas一
accounts_______(4)only about 0.4 percent of the universe.Non-luminous
components , such as black holes and intergalactic（星系间的）gas,_______(5)
up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about
73 percent.
Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people.
"We_______(8)our very existence to dark matter,"said physicist Paul
Steinhardt and a co-author of a review on dark matter which_______(9)not long ago
in the journal Science.
"Dark matter dominated the structure_______(10)in the early universe,"
Steinhardt said."For the first few billion years dark matter contained most of the mass of the
universe. You can think of ordinary matter_______(11)a froth（泡沫）of an ocean
of dark matter. The dark matter clumps（结成块）and the ordinary matter falls into it. That
_______(12) to the formation of the stars and galaxies（星系）."
Without dark matter,"there would be virtually no structures in the universe,"
The nature of dark matter is_______(13).It cannot be seen or detected
directly. Astronomers know it is there because of its_______(14) on celestial（天体
的）objects that can be seen and measured.
But the most dominating force of all in the universe is called dark energy,a recently
________(15)power that astronomers say is causing the galaxies in the universe to
separate at a faster and faster speed.
_________(6)
A:written
B:called
C:identified
D:seen
A:written
B:called
C:identified
D:seen
参考解析
解析：
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.
Smart WindowWindows not only let light in to cut down an electricity use for lighting, but the light coming through the window also provides heat. However, windows are not something people typically associate with being a cutting edge technology. Researchers are now working on new technologies that enable a window to quickly change from clear to dark and anywhere in between with a flip of a switch."It took us a long time to figure out what a window really is," says Claes Granqvist. He's a professor of solid-state physics at Uppsala University in Sweden. "It's contact with the outside world. You have to have visual contact with the surrounding world to feel well. " So, windows and natural light are important for improving the way people feel when they're stuck indoors.Yet, windows are the weak link in a building when it comes to energy and temperature control. In the winter, cold air leaks in. When it's hot and sunny, sunlight streams in. All of this sunlight carries lots of heat and energy. And all of this extra heat forces people to turn on their air conditioners. Producing blasts of cold air, which can feel so refreshing, actually suck up enormous amounts of electricity in buildings around the world.Windows have been a major focus of energy research for a long time. Over the years, scientists have come up with a variety of strategies for coating, glazing, and layering windows to make them more energy efficient. Smart windows go a step further. They use chromogenic technologies which involve changes of color.Electrochromic windows use electricity to change color. For example, a sheet of glass coated with thin layers of chemical compound such as tungsten oxide works a bit like a battery. Tungsten oxide is clear when an electric charge is applied and dark when the charge is removed, that is, when the amount of voltage is decreased, the window darkens until it's completely dark after all electricity is taken away. So applying a voltage determines whether the window looks clear or dark.One important feature that makes a smart window so smart is that it has a sort of "memory. " All it takes is a small jolt of voltage to turn the window from one state to the other. Then, it stays that way. Transitions take anywhere from 10 seconds to a few minutes, depending on the size of the window. The development of smart windows could mean that massive air conditioning systems may no longer need. "In the future," Granqvist says, "our buildings may look different. "Which of the following statements does not indicate the importance of windows as described in the first two paragraphs?A．Windows can change from clear to dark to save energy.B．Windows help to save energy by letting light in.C．Windows help to save energy by providing heat.D．Windows enable people to have contact with the outside world.
AWhen you look at the sky at night，the moon looks bigger than the stars． In fact，the moon is much smaller than the stars．It is much smaller than the earth． But the moon is much closer to us than any star． That is why it looks so big． If you hold a coin close．to your eye，it looks big．If you look at it across the room，it looks small．The moon moves around the earth． It makes one trip in about four weeks． The moon looks flat(扁的)to us． But it is a round ball，like the earth．People once thought the moon had fire(火) on it． They thought the fire made it bright．Now we know the moon is like a mirror( 镜子 )． It gets its light from the sun Our sunlight comes from the sun，too: What is the sun? The sun is star． The stars we can see have their own light． There are many big stars we can-t see． Their light has burned out． Others are still bright，but they are so far away that we can-t see them． The sun looks bigger and much brighter than other stars because it is the nearest of all stars． The sun and the other stars we see are very hot，but the air around us saves us from(使------免于) the heat(热量) of the sun．The sun gives us light and warmth．It makes plants grow and leaves turn green． It makes life possible on our earth．It is a life-giving star．( )21． The moon looks bigger because__________ ．A． some stars are smaller than itB．it is between the sun and the earthC．it is the closest to the earthD．it is very bright
Text 2 To understand how astrology works, we should first take a quick look at the sky. Although the stars are at enormous distances, they do indeed give the impression of being affixed to the inner surface of a great hollow sphere surrounding the earth. Ancient people, in fact, literally believed in the existence of such a celestial sphere. As the earth spins on its axis, the celestial sphere appears to turn about us each day, pivoting at points on a line with the earth's axis of rotation. This daily turning of the sphere carries the stars around the sky, causing most of them to rise and set, but they, and constellations they define, maintains fixed patterns on the sphere, just as the continent of Australian maintains its shape on a spinning globe of the earth. Thus the stars were called fixed stars.The motion of the sun along the ecliptic is, of course, merely a reflection of the revolution of the earth around the sun, but the ancients believed the earth was fixed and the sun had an independent motion of its own, eastward among the stars. The glare of sunlight hides the stars in daytime, but the ancients were aware that the stars were up there even at night, and the slow eastward motion of the sun around the sky, at the rate of about thirty degrees each month, caused different stars to be visible at night at different times of the year.The moon, revolving around the earth each month, also has an independent motion in the sky. The moon, however, changes its position relatively rapidly. Although it appears to rise and set each day, as does nearly everything else in the sky, we can see the moon changing position during as short an interval as an hour or so. The moon's path around the earth lies nearly in the same plane as the earth's path around the sun, so the moon is never seen very far from the ecliptic in the sky. There are five other objects visible to the naked eye that also appear to move in respect to the fixed background of stars on the celestial sphere. These are the planets Mercury, Venus, Mars, Jupiter, and the Saturn. All of them revolve around the sun in nearly the same plane as the earth does, so they, like the moon, always appear near the ecliptic. Because we see the planets from the moving earth, however, they behave in a complicated way, with their apparent motions on the celestial sphere reflection both their own independent motions around the sun and our motion as well.第26题：The ancient people believed that ________.[A] the earth was spinning on the axis of the sky[B] the sky was a hollow sphere spinning around the earth[C] the patterns of stars on the sky would never change[D] the stars around the sky were not stationary
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 is less danger after dark on a busy street than on a ______country road. A.deservedB.describedC.designedD.deserted
Have you ever seen the man in the moon?If you look (11)______ at the moon on some nights. you can see the face of the man in the moon. Some people say that they can see an old man (12) ______ sticks. Others say a girl reading. These pictures are made by the mountains and plains of the moon.Long ago people in England used to tell their children that the moon was (13)______ green cheese. Everyone knows that this is not true. The moon is a large round rock. It is completely (14)______ . There are no trees and plants of any kind on the moon. There are no rivers and seas. There are no living things. It never rains on the moon，and everything is covered with (15)______ . white dust. Not even a (16)______ can be heard on the moon.Where the sun (17)______ on it，the moon is very hot. In the dark，however, it is cold (18) ______ ice. The moon is much smaller than the earth. It does not weigh as (19)______ as the earth. If you (20)______ to the moon，you would weigh six times less than you do. Even a fat man would be able to jump high off the ground.(11)A．closelyB．scarcelyC．dailyD．immediately
共用题干Dark Forces Dominate UniverseThe earth,moon,sun and all visible stars in the sky make up less than one percent of the universe.Almost all the rest is dark matter and dark energy,unknown forces that _______(1)astronomers.Observations in recent years have changed the basic_______(2)of how the universe evolved and have indicated how little is known about the major forces and substances that_______(3)our world.Astronomers now know that luminous（发光的）matter一stars , planets and hot gas一 accounts_______(4)only about 0.4 percent of the universe.Non-luminous components , such as black holes and intergalactic（星系间的）gas,_______(5) up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about 73 percent.Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people."We_______(8)our very existence to dark matter,"said physicist PaulSteinhardt and a co-author of a review on dark matter which_______(9)not long ago in the journal Science."Dark matter dominated the structure_______(10)in the early universe," Steinhardt said."For the first few billion years dark matter contained most of the mass of the universe. You can think of ordinary matter_______(11)a froth（泡沫）of an ocean of dark matter. The dark matter clumps（结成块）and the ordinary matter falls into it. That_______(12) to the formation of the stars and galaxies（星系）."Without dark matter,"there would be virtually no structures in the universe,"The nature of dark matter is_______(13).It cannot be seen or detected directly. Astronomers know it is there because of its_______(14) on celestial（天体的）objects that can be seen and measured.But the most dominating force of all in the universe is called dark energy,a recently ________(15)power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed._________(11) A:with B:as C:from D:beside
Smart Windows 1.Windows not only let light in to cut down an electricity use for lighting, but the light coming through the window also provides heat. However, windows are not something people typically associate with being a cutting edge technology. Researchers are now working on new technologies that enable a window to quickly change from clear to dark and anywhere in between easily. 2."It took us a long time to figure out what a window really is," says Claes Granqvist. He's a professor of solid-state physics at Uppsala University in Sweden. "It's contact with the outside world. You have to have visual contact with the surrounding world to feel well." So, windows and natural light are important for improving the way people feel when they're stuck indoors. 3.Yet, windows are the weak link in a building when it comes to energy and temperature control. In the winter, cold air leaks in. When it's hot and sunny, sunlight streams in. All of this sunlight carries lots of heat and energy. And all of this extra heat forces people to turn on their air conditioners. Producing cold air, which can feel so refreshing(使人清新的), actually suck up enormous amounts of electricity in buildings around the world. 4.Windows have been a major focus of energy research for a long time. Over the years, scientists have come up with a variety of strategies for coating, glazing(用玻璃覆盖), and layering windows to make them more energy efficient. Smart windows go a step further. They use some chromogenic(发色的)technologies involving changes of color. 5.Electrochromic(电致色的) windows use electricity to change color. For example, a sheet of glass coated with thin layers of tungsten oxide(氧化钨)works a bit like a battery. Tungsten oxide is clear when an electric charge is applied and dark when the charge is removed, that is, when the amount of voltage(电压)is decreased, the window darkens until it's completely dark after all electricity is taken away. So applying a voltage determines whether the window looks clear or dark. 6.One important feature that makes a smart window so smart is that it has a sort of "memory". All it takes is a small shock of voltage to turn the window from one state to the other. Then, it stays that way. Transitions take from 10 seconds to a few minutes, depending on the size of the window. The development of smart windows could mean that massive air conditioning systems may no longer need. "In the future," Granqvist says, "our buildings may look different."文章(31~35)Which of the following values of windows is NOT mentioned?A.They let light in to brighten the house.B.They let light in to heat the house.C.They let us have visual contact with the surrounding world.D.They let us think about the outside world.
共用题干Dark Forces Dominate UniverseThe earth,moon,sun and all visible stars in the sky make up less than one percent of the universe.Almost all the rest is dark matter and dark energy,unknown forces that _______(1)astronomers.Observations in recent years have changed the basic_______(2)of how the universe evolved and have indicated how little is known about the major forces and substances that_______(3)our world.Astronomers now know that luminous（发光的）matter一stars , planets and hot gas一 accounts_______(4)only about 0.4 percent of the universe.Non-luminous components , such as black holes and intergalactic（星系间的）gas,_______(5) up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about 73 percent.Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people."We_______(8)our very existence to dark matter,"said physicist PaulSteinhardt and a co-author of a review on dark matter which_______(9)not long ago in the journal Science."Dark matter dominated the structure_______(10)in the early universe," Steinhardt said."For the first few billion years dark matter contained most of the mass of the universe. You can think of ordinary matter_______(11)a froth（泡沫）of an ocean of dark matter. The dark matter clumps（结成块）and the ordinary matter falls into it. That_______(12) to the formation of the stars and galaxies（星系）."Without dark matter,"there would be virtually no structures in the universe,"The nature of dark matter is_______(13).It cannot be seen or detected directly. Astronomers know it is there because of its_______(14) on celestial（天体的）objects that can be seen and measured.But the most dominating force of all in the universe is called dark energy,a recently ________(15)power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed._________(1)A:worry B:move C:puzzle D:reject
共用题干Dark Forces Dominate UniverseThe earth,moon,sun and all visible stars in the sky make up less than one percent of the universe.Almost all the rest is dark matter and dark energy,unknown forces that _______(1)astronomers.Observations in recent years have changed the basic_______(2)of how the universe evolved and have indicated how little is known about the major forces and substances that_______(3)our world.Astronomers now know that luminous（发光的）matter一stars , planets and hot gas一 accounts_______(4)only about 0.4 percent of the universe.Non-luminous components , such as black holes and intergalactic（星系间的）gas,_______(5) up 3.6 percent.The rest is either dark matter,about 23 percent,or dark energy,about 73 percent.Dark matter,sometimes_______(6)"cold dark matter,"has been known for some time.Only recently have researchers come to understand the key role it_______ (7)in the formation of stars,planets and even people."We_______(8)our very existence to dark matter,"said physicist PaulSteinhardt and a co-author of a review on dark matter which_______(9)not long ago in the journal Science."Dark matter dominated the structure_______(10)in the early universe," Steinhardt said."For the first few billion years dark matter contained most of the mass of the universe. You can think of ordinary matter_______(11)a froth（泡沫）of an ocean of dark matter. The dark matter clumps（结成块）and the ordinary matter falls into it. That_______(12) to the formation of the stars and galaxies（星系）."Without dark matter,"there would be virtually no structures in the universe,"The nature of dark matter is_______(13).It cannot be seen or detected directly. Astronomers know it is there because of its_______(14) on celestial（天体的）objects that can be seen and measured.But the most dominating force of all in the universe is called dark energy,a recently ________(15)power that astronomers say is causing the galaxies in the universe to separate at a faster and faster speed._________(13) A:unknown B:interesting C:different D:visible
共用题干Global WarmingFew people now question the reality of global warming and its effects on the world's climate. Many scientists1the blame for recent natural disasters on the increase2the world's temperatures and are convinced that,more than3before,the Earth is at4from the forces of the wind,rain and sun.5to them,global warming is making extreme weather events,6as hurricanes and droughts,even more7and causing sea levels all around the world to8.Environmental groups are putting9on governments to take action to reduce the 10 of carbon dioxide which is given 11 by factories and power plants,thus attacking the problem at its source. They are in12of more money being spent on research into so-lar,wind and wave energy devices,which could then replace existing power13.Some scientists,14believe that even if we stopped releasing carbon dioxide and other gases into the atmosphere tomorrow,we would have to wait15hundred years to notice the results. Global warming,it seems,is here to stay.11._________A: off B: away C: up D: over
共用题干第一篇TourismPeople travel for a lot of reason.Some tourists go to see battlefields or religious shrines.Others are looking for culture,or simply want to have their picture taken in front of famous places.But most European tourists are looking for a sunny beach to lie on.Northern European are willing to pay a lot of money and put up with a lot of inconveniences for the sun because they have so little of it. Residents of cities like London,Copenhagen,and Amsterdam spend a lot of their winter in the dark because the days are so short,and much of the rest the year in the rain.This is the reason the Mediterranean has always attracted them.Every summer, more than 25 million people travel to Mediterranean resort and beaches for their vacation.They all come for the same reason:sun!The huge crowds mean lots of money for the economies of Mediterranean countries.Italy's30,000 hotels are booked solid every summer.And 13 million people camp out on French beaches, parks and roadsides.Spain's long sandy coastline attracts more people than anywhere else.37 million tourists visit yearly,or one tourist for every person living in Spain.But there are signs that the area is getting more tourism than it can hand1e; The Mediterranean is already one the most polluted seas on earth.And with increased tourism,it's getting worse.The French can't figure out what to do with all the garbage left by campers around St. Tropez.And in many places,swimming is dangerous because of pollution.None of this,however,is spoiling anyone's fun.The Mediterranean gets more popular every year with tourists.Obviously,they don't go there for clean water and solitude.They tolerate traffic jams and seem to like crowded beaches.They don't even mind the pollution.No matter how dirty the water is,the coastline still looks beautiful.And as long as the sun shines,it's still better than sitting in the cold rain in Berlin,London,or Oslo.The writer seems to imply that Europeans travel mostly for the reason that______.A:they want to see historic remains or religious spotsB:they are interested in different cultural traditions and social customsC:they would like to take pictures in front of famous sitesD:they wish to escape from the cold,dark and rainy days back at home
共用题干Modern Sun Worshippers People travel for a lot of reasons.Some tourists go to see battlefields or religious shrines.Others are looking for culture,or simply want to have their pictures taken in front of famous places.But most European tourists are looking for a sunny beach to lie on. Northern Europeans are willing to pay a lot of money and put up with a lot of inconveniences for the sun because they have so little of it.Residents of cities like London,Copenhagen,and Amsterdam spend a lot of their winter in the dark because the days are so short,and much of the rest of the year in the rain.This is the reason why the Mediterranean has always attracted them.Every summer,more than 25 million people travel to Mediterranean resorts and beaches for their vacation.They all come for the same reason:sun! The huge crowds mean lots of money for the economies of Mediterranean countries.Italy's30,000 hotels are booked solid every summer.And 13 million people camp out on French beaches,parks,and roadsides.Spain's long sandy coastline attracts more people than anywhere else.37 million tourists visit yearly,or one tourist for every person living in Spain. But there are signs that the area is getting more tourism than it can handle.The Mediterranean is already one of the most polluted seas on earth.And with increased tourism,it's getting worse.The French can't figure out what to do with all the garbage left by campers around St.Tropez.And in many places, swimming is dangerous because of pollution. None of this,however,is-spoiling anyone's fun.The Mediterranean gets more popular every year with tourists.Obviously,they don't go there for clean water and solitude.They tolerate traffic jams and seem to like crowded beaches.They don't even mind the pollution.No matter how dirty the water is,the coastline still looks beautiful.And as long as the sun shines,it's still better than sitting in the cold rain in Berlin,Iondon,or Oslo.Every summer,all of Italy's 30,000 hotels are booked by travelers.A:Right B:Wrong C:Not mentioned
共用题干Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive（原始的）man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship（崇拜）a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve（曲线）of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling（闪烁）lights. Some early astronomers（天文学家）believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it.Paragraph 2_________A:Early Ideas about the Sky and the StarsB:The Importance of the Sun to Life on EarthC:Primitive Knowledge of the MoonD:The Sun in Autumn and WinterE:Early Ideas about the EarthF:Collecting Evidence about the Sun
共用题干Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive（原始的）man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship（崇拜）a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve（曲线）of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling（闪烁）lights. Some early astronomers（天文学家）believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it.Early man thought the earth was small and flat because_________.A:he did not observe the sun carefully enoughB:he could not see its curveC:the sun,the moon and the stars seemed to move around itD:the earth circles around the sunE:it looked like that at nightF:it has power over life on earth
共用题干Weight on and off the Earth We are so used to.our life on the surface of the earth that it can be quite an effort for our mind to break free of all the ideas that we take for granted.Because we can feel that things are heavy,we think of "weight"as being a fixed quality in an object,but it is not really fixed at all.If you could take a one-pound packet of butter 4,000 miles out from the earth,it would weigh only a quarter of a pound. Why would things weigh only a quarter as much as they do at the surface of the earth if we took them 4,000 miles out into space?The reason is this:all objects have a natural attraction for all other objects;this is called gravitational attraction.But this power of attraction between two obects gets weaker as they get farther apart.When the butter was at the surface of the earth,it was 4,000 miles from the center.When we took the butter 4,000 miles out,it was 8,000 miles from the center,which is twice the distance.If you double the distance between two objects,their gravitational attraction decreases two times two.If you treble the distance, it gets nine times weaker(three times three)and so on. So this is one of the first things we need to remember that the weight of an object in space is not the same as its weight on the surface of the earth. What about the weight of our pound of butter on the surface of the moon?At the distance the puii of the earth is about 4,000 times smaller than it is here on the surface,so we can forget all about the earth-pull on our butter. On the other hand,on the moon there will be an attraction between the butter and the moon,but the butter will weigh only about one-sixth as much as it does on the earth.This is because the moon is so much smaller than the earth.The amount of gravitational pull that a body produces depends on the amount of material in it.A packet of butter has a gravitational pull of its own;but this is very small in relation to the pull of something as large as the moon,or the earth,or the sun.How much would four pounds of tea weigh if it was taken 4,000 miles out from the surface of the earth?A:1 pound. B:2 pounds. C:3 pounds. D:4 pounds.
共用题干Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive（原始的）man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship（崇拜）a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve（曲线）of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling（闪烁）lights. Some early astronomers（天文学家）believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it.Primitive man believed the sun was a god because_________.A:he did not observe the sun carefully enoughB:he could not see its curveC:the sun,the moon and the stars seemed to move around itD:the earth circles around the sunE:it looked like that at nightF:it has power over life on earth
共用题干Early Ideas about the Universe1 Early man got his ideas about the universe by looking at the stars as you do.He observed carefully,and learned many things about the sun,the moon,and the stars.2 Suppose you were asked to collect evidence about the sun as early man did.You might go out morning after morning and see it come up in the east.Even on cloudy mornings,youwould observe that the darkness goes away and the world becomes light.You might not see the sun but would be sure it is there,because you notice that the earth warms up.As you continued,the sun climbs higher in the sky each day during part of the year. It stays in the sky longer. The earth gets warmer. Things begin to grow. It is spring and then summer.3 After a while the sun stays in the sky for shorter and shorter periods.Many plants begin to die.Leaves fall.Winter comes.Year after year this is repeated and you cannot tell exactly why it happens.But you realize that the sun seems to make the difference. Primitive（原始的）man felt that since the sun was so powerful it must be a god. It may seem silly to us now to worship（崇拜）a sun-god, but primitive man was right about the importance of the sun to life on earth.4 You have been told that the world is round.But suppose no one had ever taught you that the world was like a huge ball.Would you have ever thought of it yourself?You cannot see the curve（曲线）of the earth at once. You would have no idea of how big it was. That's why early man believed that the earth was small and flat.Such ideas appeared from the evidence they had.5 If you watch the stars night after night,you will see them rise and set.As you look at the sky,it is not difficult to imagine that you are in the center of a vast collection of twinkling（闪烁）lights. Some early astronomers（天文学家）believed the sky was a crystal shell or series of crystal shells,one inside the other. They believed this because that is what the night sky looked like.For many centuries,men believed that the earth was the center of the universe and that the sun,the moon,and the stars circled around it.Early astronomers believed that the sky was a crystal shell or series of crystal shells because_________.A:he did not observe the sun carefully enoughB:he could not see its curveC:the sun,the moon and the stars seemed to move around itD:the earth circles around the sunE:it looked like that at nightF:it has power over life on earth
How much is the percent of air transportation in all modes?（）A、Less than 1%B、LowestC、LowerD、Low
单选题They had the appearance of dark-skinned and dark-haired humans, _______ of course they were much smaller than ordinary people.AhoweverBalthough Cwhile Dnevertheless
单选题During volcanic _____, dark clouds of smoke fill the sky, bringing fears to local residents.AeruptionBejectionCerosionDerection
单选题_____ he realized it was too late to return home.ANo sooner it grew dark whenBIt was not until dark thatCScarcely it grew dark thanDWhile it grew dark that
单选题We learn from the passage that ______.Aall living things on the earth depend on the sun for their foodBa forest looks dark in winter because it absorbs solar energyConly 0.023 of the energy from the sun is made use of on the earthDgreenhouse gases allow heat energy to escape from the earth’ s surface
单选题As a white dwarf, the sun will be.Athe same size as the planet MercuryBthousands of times smaller than it is todayCaround 35 million miles in diameterDcold and dark
单选题They had the appearance of dark-skinned and dark-haired humans, _____ of course they were much smaller than ordinary people.AhoweverBalthoughCwhileDnevertheless