共用题干第二篇Night of the Living AntsWhen an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-tists,who wonder how ants know for sure一and so soon一that another ant is dead.Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical on the outside of their bodies that signals to other ants,"I'm dead一take me away."But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls around,perhaps in a picnic or home,it's telling other ants that it's dead.What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not dead yet."Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knockedunconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be alive.Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-tect the remaining"dead"chemical and remove the body from the nest.According to Choe's hypothesis,_______________.A:an ant still smells like a living one when it diesB:the"I am dead"chemical leaves the ant's body when it diesC:the"I am not dead yet"chemical is left when an ant diesD:the"I am not dead yet"chemical quickly goes away when it dies
共用题干
第二篇
Night of the Living Ants
When an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-
tists,who wonder how ants know for sure一and so soon一that another ant is dead.
Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical
on the outside of their bodies that signals to other ants,"I'm dead一take me away."
But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says
that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls
around,perhaps in a picnic or home,it's telling other ants that it's dead.
What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional
chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's
research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not
dead yet."
Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knocked
unconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be
alive.
Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly
goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant
no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases
new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not
dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.
To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When
the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-
entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes
this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up
by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-
tect the remaining"dead"chemical and remove the body from the nest.
第二篇
Night of the Living Ants
When an ant dies,other ants move the dead insect out of the nest.This behavior is interesting to scien-
tists,who wonder how ants know for sure一and so soon一that another ant is dead.
Dong-Hwan Choe,a scientist at the University of California,found that Argentine ants have a chemical
on the outside of their bodies that signals to other ants,"I'm dead一take me away."
But there's a twist to Choe's discovery. These ants behave a little bit like zombies（僵尸）.Choe says
that the living ants一not just the dead ones一have this death chemicals. In other words,while an ant crawls
around,perhaps in a picnic or home,it's telling other ants that it's dead.
What keeps ants from hauling away the living dead? Choe found that Argentine ants have two additional
chemicals on their bodies,and these tell nearby ants something like,"Wait一I'm not dead yet."So Choe's
research turned up two sets of chemical signals in ants:one says,"I'm dead,"the other set says,"I'm not
dead yet."
Other scientists have tried to figure out how ants know when another ant is dead.If an ant is knocked
unconscious,other ants leave it alone until it wakes up.That means ants know that unmoving ants can still be
alive.
Choe suspects that when an Argentine ant dies,the chemical that says"Wait一I'm not dead yet"quickly
goes away. Once that chemical is gone,only the one that says"I'm dead"is left."It's because the dead ant
no longer smells like a living ant that it gets carried to the graveyard（墓地）,not because its body releases
new,unique chemicals after death,"said Choe.When other ants detect the"dead"chemical without the"not
dead yet" chemical,they haul away the body. This was Choe's hypothesis（假设）.
To test his hypothesis,Choe and his team put different chemicals on Argentine ant pupae（蛹）.When
the scientists used the"I'm dead"chemical,other ants quickly hauled the treated pupae away.When the sci-
entists used the"Wait一I'm not dead yet"chemical,other ants left the treated pupae alone.Choe believes
this behavior shows that the" not dead yet" chemical overrides（优先于）the" dead" chemical when picked up
by adult ants.And that when an ant dies,the"not dead yet"chemical fades away.Other nearby ants then de-
tect the remaining"dead"chemical and remove the body from the nest.
According to Choe's hypothesis,_______________.
A:an ant still smells like a living one when it dies
B:the"I am dead"chemical leaves the ant's body when it dies
C:the"I am not dead yet"chemical is left when an ant dies
D:the"I am not dead yet"chemical quickly goes away when it dies
A:an ant still smells like a living one when it dies
B:the"I am dead"chemical leaves the ant's body when it dies
C:the"I am not dead yet"chemical is left when an ant dies
D:the"I am not dead yet"chemical quickly goes away when it dies
参考解析
解析：第二段提到：加州大学的科学家周东环发现阿根廷蚂蚁的身体能向外释放一种化学物 质来告诉同伴：“我死了，把我挪走吧。”
根据第五段第二句可推断出C项错误。
倒数第二段提到：一只阿根廷蚂蚁死后，发出“等等，我还没死呢”这一信号的化学物质 立刻消失，因此选D。
周的假设是表明“我死了”的化学物质是蚂蚁本身就有的，而非死后释放的。它和表明 “我没死”的化学物质同时存在于活着的蚂蚁身上，只不过其优先权不如表明“我没死”的化学 物质。实验结果是：当科学家用“我已死”化学物质时，蚂蚁们立刻将处理过的蛹拉走。当科 学家使用“等等，我还没死”化学物质时，其他蚂蚁并不碰这个蛹。所以，周的假设是正确的。
本文主要讲述了蚂蚁们如何迅速准确地得知同伴死了，所以选D。 第三篇 本文介绍了在山口发现的一具躺在冰上的尸体，以及由此引发的研究和种种猜测。
根据第五段第二句可推断出C项错误。
倒数第二段提到：一只阿根廷蚂蚁死后，发出“等等，我还没死呢”这一信号的化学物质 立刻消失，因此选D。
周的假设是表明“我死了”的化学物质是蚂蚁本身就有的，而非死后释放的。它和表明 “我没死”的化学物质同时存在于活着的蚂蚁身上，只不过其优先权不如表明“我没死”的化学 物质。实验结果是：当科学家用“我已死”化学物质时，蚂蚁们立刻将处理过的蛹拉走。当科 学家使用“等等，我还没死”化学物质时，其他蚂蚁并不碰这个蛹。所以，周的假设是正确的。
本文主要讲述了蚂蚁们如何迅速准确地得知同伴死了，所以选D。 第三篇 本文介绍了在山口发现的一具躺在冰上的尸体，以及由此引发的研究和种种猜测。
相关考题：
共用题干Cell Phone Lets Your Secret OutYour cell phone holds secrets about you.Besides the names and _____________(51)that you've pro-grammed into it,traces of your DNA linger on the device,according to a new study.DNA is genetic material that______________(52)in every cell.Like your fingerprint,your DNA is uniqueto you一 _____________（53)you have an identical twin.Scientists today routinely analyze DNA in blood,saliva,or hair left _____________(54)at the scene of a crime.The results often help detectives identify_____________(55)and their victims.Your cell phone can reveal more about you _____________(56)you mightthink. Meghan J.McFadden,a scientist at McMaster University in Hamilton,Ontario,heard about a crime in which the suspect bled onto a cell phone and later dropped the______________(57).This made her wonder whether traces of DNA lingered on cell phones even when no blood was involved.______________(58)she and colleague Margaret Wallace of the City University of New York analyzed the flip-open phones of 10 volun- teers.They used swabs to collect______________(59)traces of the users from two parts of the phone:the outside,where the user holds it,and the______________(60),which is placed at the user's ear.The scientists scrubbed the phones using a solution made mostly______________(61)alcohol.The aim of washing was to remove all detectable traces of DNA.The owners got their phones______________(62)for another week.Then the researchers collected the phones and repeated the swabbing of each phone once more.The scientists discovered DNA that _____________(63)to the phone's speaker on each of the phones.Better samples were collected from the outside of each phone,but those swabs also picked up DNA that be- longed to other people who had apparently also handled the phone.______________(64),DNA showed up even in swabs that were taken immediately after the phones were scrubbed.That suggests that washing won't removeall traces of evidence from a criminal's device.So cell phones can now be added to the______________(65)of clues that can clinch a crime-scene investigation._________(56)A:whenB:untilC: beforeD:than
共用题干第一篇Walking to Exercise the BrainDo you think sitting and studying all the time will improve your grades?Think again.Getting some exer-cise may help,too.New research with old people suggests that taking regular walks helps them pay attention better than if they didn't exercise.Previous research had shown that mice learn,remember,and pay attention better after a few weeks of working out on a running wheel.Mice that exercise have greater blood flow to the brain than those who don't. Their brain cells also make more connections.Neuroscientists（神经科学家）from the University of Illinois at Urbana Champaign wanted to find out if the same thing is true for people.First,they measured the physical fitness of 41 adults,ages 58 to 77,after each person walked 1 mile.Then,participants looked at arrows on a computer screen and had to use computer keys to show which way one particular arrow was pointing.Adults who were physically fit were faster at the arrow task,and their answers were just as accurate as their less-fit peers,the researchers found.The fitter participants also had more blood flow to a part of theirbrain responsible for paying attention and making decisions.In a second study , 15 elderly people who completed a 6-month aerobic-training（有氧运动）course were faster at attention tasks compared with 14 seniors who just did stretching and toning exercises（韵律操）for the same amount of time.So,even going for a walk every 2 or 3 days for just 10 to 45 minutes can help.That should be good news for the elderly.The effects of exercising on the brains of younger people haven't been studied yet. Still,it can't hurt to take occasional breaks and go for a walk or run around with friends.Whatever you do,though,don't try to read and walk at the same time.You could end up hurting yourself!After taking exercise for a few weeks,the mice were found to have______________ A:higher blood pressureB:faster heartbeatC:more blood flow to the brain D:better appearance
共用题干SleepSleep is part of a person's daily activity cycle .There are several different stages of sleep,and they too occur in cycles.______(46)When you first drift off into slumber,your eyes will roll about a bit,your temperature will drop slightly,your muscles will relax,and your breathing will slow and become quite regular. Your brain waves slow down a bit too,with the alpha rhythm of rather fast waves predominating for the first few minutes.______(47)For the next half hour or so,as you relax more and more,you will drift down through stage 2 and stage 3 sleep.______(48)Then about 40 to 60 minutes after you lose consciousness you will have reached the deepest sleep of all.Your brain waves will show the large slow waves that are known as the delta rhythm. This is stage 4 sleep.You do not remain at this deep fourth stage all night long,but instead about 80 minutes after you fall into slumber,your brain activity level will increase again slightly. ______(49)Your eyes will begin to dart around under your closed eyelids as if you were loo-king at something occurring in front of you.______(50)It is during REM sleep period,your body will soon relax again,your breathing will grow slow and regular once more,and you will slip gently back from stage 1 to stage 4 sleep-only to rise once again to the surface of near consciousness some 80 minutes later.______(50)A: The delta rhythm will disappear,to be replaced by the activity pattern of brain waves.B: If you are an average sleeper,your sleep cycle is as follows.C: In stage 4 sleep people tend to dream.D: The lower your stage of sleep,the slower your brain waves will be.E: This period of rapid eye movement lasts for some 8 to 15 minutes and is called REM sleep.F: This is called stage 1 sleep.
共用题干第三篇On the Trail of the Honey BadgerOn a recent field trip to the Kalahari Desert,a team of researchers learnt a lot more about honey badgers（獾）.The team employed a local wildlife expert,Kitso Khama,t& help them locate and follow the badgers across the desert.Their main aim was to study the badgers'movements and behaviour as discreetly （谨慎地）as possible,without frightening them away or causing them to change their natural behaviour. Theyalso planned to trap a few and study them close up before releasing them.In view of the animal's reputation, this was something that even Khama was reluctant to do. "The problem with honey badgers is that they are naturally curious animals, especially when they see something new,"he says. "That, combined with their unpredictable nature,can be a dangerous mixture. If they sense you have food ,for example , they won't be shy about coming right up to you for something to eat. They're actually quite sociable creatures around humans ,but as soon as ther feel they might be in danger, they can become extremely vicious（凶恶的）.Fortunately this is rare ,but it does happen."The research confirmed many things that were already known.As expected , honey badgers ate any crea- tures they could catch and kill. Even poisonous snakes , feared and avoided by most other animals,were not safe from them. The researchers were surprised , however, by the animal' s fondness for local melons , probably because of their high water content. Previously researchers thought that the animal got all of its liquid require- ments from its prey（猎物）.The team also learnt that , contraryto previous research findings, the badgers oc- casionauy formed loose famiiy groups. They were also able to confirm certain results Irom previous research,including the fact that female badgers never socialised with each other.Following some of the male badgers was a challenge,since they can cover large distances in a short space of time. Some hunting territories cover more than 500 square kilometers. Although they seem happy to share these territories with other males,there are occasional fights over an important food source, and male badgers can be as aggressive towards each other as they are towards other species.As the badgers became accustomed to the presence of people , it gave the team the chance to get up close to them without being the subject of the animals'curiosity-or their sudden aggression. The badgers'eating patterns, which had been disrupted,returned to normal. It also allowed the team to observe more closely some of the other creatures that form working associations with the honey badger, as these seemed to adopt the badgers' relaxed attitude when near humans. What did the team find out about honey badgers?A: There~~creatures they did not eat.B: They were afraid of poisonous creatures.C: Female badgers did not mix with male badgers.D: They may get~of the water they needed from fruit.
共用题干Virtual DriverDriving involves sharp eyes and keen ears,analyzing with a brain,and coordination between hands,feet and brain.A man has sharp eyes and keen ears,analyzes through his brain,and maintains coordination between his hands and brains.He can control a fast-moving car with different parts of his body._______(46)Apparently there isn't anyone in the driver's cab,but there is in fact a virtual driver. This virtual driver has eyes,brains,hands and feet too.The minicameras on each side of the car are its eyes and are responsible for observing the road conditions ahead of it as well as the traffic to its left and right.If you open the boot,you can see the most important part of the automatic driving system:a built-in computer._______(47)The brain is responsible for calculating the speeds objects surrounding the car are moving at,analyzing their position on the road, choosing the right path,and giving orders to the wheel and the control system.In comparison with the human brain,the virtual driver's best advantage is that it reacts quickly. _______(48)However,it takes the world's best racecar driver at least one second to react,and this doesn't include the time he needs to take action.With its rapid reaction and accurate control,the virtual driver can reduce the accident rate on expressways considerably.In this case,is it possible for us to let it have the wheel at any time and in any place?_______(49)With its limited ability to recognize things,the car can now only travel on expressways.The intelligent car determines its direction by the clear lines that mark the lanes clearly and recognizes vehicles according to their regular shapes._______(50)This being the case,people still have high hopes about driverless cars,and think highly intelligent cars are what the cars of the future should be like.________（46）A:Experts say that we cannot do that just yet.B:In the near future,intelligent cars will be put into commercial operation.C:This is the brain of the car.D:But how does an intelligent car control itself?E:It completes the processing of the images sent by the cameras within 100 milliseconds.F:However,it cannot recognize moving people and bicycles on ordinary roads that have no clear markings on them.
It frustrates me that I'm not able to put any of my ideas into practice.A: discouragesB:showsC:surprisesD:frightens
She only needs a minute amount of money.A:.certainB: fairC: fullD: small