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Do scientists know how many cryptic species exist？A．Not yet.B．Yes, they do.C．They will kno

Do scientists know how many cryptic species exist？

A．Not yet.

B．Yes, they do.

C．They will know the answer in another one or two years.

D．They will never know the answer.

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更多“Do scientists know how many cr…”相关的问题

第1题

How do scientists know Motherhood may make women smarter（）

A．Some researchers have told them

B．Many women say so

C．They know it by experimenting on rats

D．They know it through their own experience

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第2题

Why do scientists know black holes exist（).

A、They are much larger than other stars.

B、They exert a force of gravity on other stars.

C、They are visible with special telescopes.

D、It is possible to calculate their mass and energy.

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第3题

Scientists hope that if we can discover __1__ the brain works, the better use we will

be able to put it to. For example, how do we learn language？ Man differs most from all the animals in his ability to learn and use language __2__ we still do not know exactly how this is done. Some children learn to speak and read and write when they are very young compared to __3__ children. But scientists are not sure why this happens. They are trying to find out __4__ there is something about the way we teach language to children which in fact prevents children __5__ learning sooner.

1)、A.but

B.how

C.from

D.whether

E.average

2)、A.but

B.how

C.from

D.whether

E.average

3)、A.but

B.how

C.from

D.whether

E.average

4)、A.but

B.how

C.from

D.whether

E.average

5)、A.but

B.how

C.from

D.whether

E.average

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第4题

CAN ANIMALS BE MADE TO WORK FOR US？ Can animals be made to work for us？ Some scientists think that one day animals may be trained to do a number of simple jobs that are now done by human beings. The

21. Now many animals can do some simple jobs that are done by human beings.

22. The writer says that 8t a circus we can see animals doing cIever tricks.

23. The trainer usually gives the animal a piece of candy or fruit after it has done the trick.

24. The reward in the passage means "attention paid to a good behavior".

25. Many animals may be trained to do simple jobs if they know who their trainers are.

26. Geese can be used to guard a house.

27. When the pigeon sees a ball which looks different from the others , it makes a noise.

28. Trainer usually spends 40 days or so training a pigeon to inspect sm811 steel balls.

29. An ape is a large monkey.

30. Scientists believe apes may drive buses one day.

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第5题

Whom do you know better, ______ ？ A．his friend or her B．her or his C．his or her friend D．her or h

Whom do you know better, ______ ？

A．his friend or her B．her or his

C．his or her friend D．her or his friend

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第6题

"Do you know （) he got the highest mark in the English exam？" "Yes. He h

A."

B.what

C.how

D.when

E.why

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第7题

–Do you know if Jck will drive to London this weekend －－Jck Never! He_____ driving so fr.

–Do you know if Jck will drive to London this weekend －－Jck Never! He_____ driving so fr.hs h–Do you know if Jck will drive to London this weekend --Jck Never! He_____ driving so fr.hs hted B．will hte C．hted D．htes

A．has hated

B．will hate

C．hate

D．hates

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第8题

根据以下内容，回答题。Passage OneCan animals be made to work for us？ Some scientists think t

根据以下内容，回答题。

Passage One

Can animals be made to work for us？ Some scientists think that one day animals may be trained to do a number of simple jobs that are now done by human beings.

They point out that at a circus， for example， we may see elephants， monkeys， dogs and other animals doing quite skillful things. Perhaps you have seen them on the television or in a film. If you watch closely， you may notice that the trainer always gives the animal a piece of candy or a piece of fruit as a reward. The scientists say that many different animals may be trained to do a number of simple jobs if they know they will get a reward for doing them.

Of course， as we know， dogs can be used to guard a house， and soldiers in both old and modem times have used geese to give warning by making a lot of noise when a stranger or an enemy comes near. But it may be possible to train animals to work in factories. In Russia， for example， pigeons which are birds with good eyesight， are being used to watch out for faults in small steel balls that are being made in one factory. When the pigeon sees a ball which looks different from others， it touches a steel plate with its beak. This turns on a light to warn people in the factory. At the same time a few seeds are given as a reward. It takes three to five weeks to train a pigeon to do this and one pigeon can inspect 3 000 to 4 000 balls an hour.

Apes have been used in America in helping to make cars， and scientists believe that these large monkeys may be one day gather crops and even drive trains.

What made scientists think animal can be made to work for us one day？查看材料

A.Animals are very skillful at a circus.

B.They are big and strong.

C.Some animals are as clever as human beings.

D.Animals can be trained because they like to get something as a reward.

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第9题

Over eight months the scientists tested 20 drugs, all with negative results. Finall

y they tested the anticonvulsant drug ethosuzimide. Researchers found that the drug extended the life span of roundworms from 16. 7 days to 19. 6 days, a 17 percent increase。

A. But Komfeld said scientists will not know about the applicability of the drugs in humans until a similar study is done on humans. “What’s very encouraging is that these drugs were developed to treat humans, and they are well understood, because they’ve been used for a long time, ” he said。

B. Later the scientists discovered that two related anticonvulsant drugs also lengthened the lives of the worms-in the case of one drug, by almost 50 percent. “This was a big surprise to use, Komfeld said. ”“We didn’t think anticonvulsant drugs had any particular relationship to aging. That connection was completely unexpected. ”

C. Roundworms are a poor subject for experiments, because they are not like humans, even though their molecules are similar. For example, they have no bones, nor do they show emotions, making it difficult to know how exactly human subjects would react to these drugs in large quantities. However, using the worms allows experiments to be conducted quickly, because they do not live for long。

D. “Somehow the neural activity seems to regulate the aging of all of the body the skin, musculature, and reproductive tract, ” Kornfeld said. “Somehow the nervous system coordinates the progress of all these tissues, evidently, though the life stages. But we don’t know how it does that. ”

E. The discovery may also shed light on the little-understood aging process. Since the drugs act on the neuromuscular systems of both humans and worms, the findings hint at a link between neural activity and aging。

F. Unlike vertebrates, the worms are ideal subjects for the study of aging because of their short life spans, which last only a couple of weeks in a laboratory. The worm is well known in genetics, and the worm’s genome has been sequenced。

G. Use of this drug has been permitted by law since 1998 and wider use is now expected as a result of the studies. “We can clearly link this drug with human aging, but we still need to find proof, says Kornfeld optimistically. ”

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第10题

This is not the world we know. This world is controlled by computers. Men and women can

be seen, but they are following the orders given to them by machines. The machines were designed by mad scientists, but at some point even the mad scientists were taken over by their super-inventions.

Does this sound familiar？ You have probably read something like it in magazines or books, or seen it in a film. Why is it so popular？ One of the reasons is that it reflects the fears of many people; fear of the unknown fear of what is not understood or, at least, fear of something that is not completely understood.

The fact is that every day it seems that computers take control of another area of our lives. Some

factory jobs are now done by robots and the robots are controlled by computers. Our bank accounts are managed by computers. At the airport, our tickets are sold by a computer. Certainly, many of these operations are made more

efficient by computers, but our admiration is sometimes mixed with unsafe feelings. And this lack of safety is caused by the fact that we do not know how computers do these things, and we really don't know what they might do next. But we can find out how computers work, and once we understand them, we can use computers instead of worrying about being used by them. Today, there is a new generation of computer wizards who know exactly how computers get things done. These young men and women, usually university students, are happy to sit for hours, sometimes for days, designing programs, not eating, not sleeping, but discovering what can be done by these wonderful slaves which they have learned to control. These computer wizards have learned to use the computer and search for new tasks for their machines.

(1)、According to the passage, our present world is under the control of ______ .

A：mad scientists

B：men and women

C：the unknown fear

D：some super-inventions

(2)、The reason why many people are afraid of computers is that ______ .

A：they don't know anything about computers

B：they haven't really understood computers

C：there are so many computer games

D：computers are often down

(3)、The author mentions computer wizards in order to point out that ______ .

A：computers can be controlled by man