题目内容
They cannot find enough (足够的) food and water ______.
[ ]
A. to eat and drinking B. eating and to drink
C. eating and drinking D. to eat and drink

Do you know why different animals or pests (昆虫) have their special colors? Colors in them seem to be used mainly to protect themselves.
Some birds like eating locusts (蝗虫), but birds cannot easily catch them. Why? It is because locusts change their colors together with the change of the colors of crops(庄稼). When crops are green, locusts look green. But as the harvest time comes, locusts change to the same brown color as crops have. Some other pests with different colors from plants are easily found and eaten by others. So they have to hide themselves for lives and appear only at night.
If you study the animal life, you’ll find the main use of coloring is to protect themselves. Bears, lions and other animals move quietly through forests. They cannot be easily seen by hunters (猎人). This is because they have the colors much like the trees.
Have you ever noticed an even stranger act? A kind of fish in the sea can send out a kind of very black liquid (液体)when it faces danger. While the liquid spreads over (散开), its enemies (敌人)cannot find it. And it immediately swims away. So it has lived up to now though it is not strong at all.
【小题1】From the passage we learn that locusts________.
A.are small animals | B.are easily found by birds |
C.are dangerous to their enemies | D.change their colors to protect themselves |
A.They run away quickly. | B.They have the colors much like their enemies. |
C.They hide themselves by day and appear at night. | D.They have to move quietly. |
A.they have the colors much like the trees | B.they move quietly |
C.they like brown and gray colors | D.they live in forests |
A.Because it is very and strong. |
B.Because the liquid it sends out can help it escape from its enemies. |
C.Because the liquid it sends out can kill its enemies. |
D.Because it swims faster than any other fish. |
A.The Change of Colors for Animals and Pests | B.Colors of Different Animals and Pests |
C.The Main Use of Colors for Animals and Pests | D.Some Animals and Pests |
In some science fiction movies, evil robots refuse to die, no matter how hard people fight back.
Now science fiction has become science fact. For the first time, scientists have made a robot that can take a beating(挨打) and keep on going. Scientists from Cornell University made the robot, which looks like a spider with four legs.
Until now, even the most advanced(先进的) robot was almost certain to break down when it was damaged(毁坏). That is because its computer inside simply doesn’t know how to make the machine work after its shape has changed.
To deal with this problem, the scientists put eight motors(发动机) and two sensors(传感器) that read how the machine is working. They all give signals to the machine’s software. Using this information, the computer can then figure out the machine’s shape at any moment.
The new technology is a big advance in robot-making, scientists say, and it’s far from scary. It may someday help scientists create better artificial(假的) arms and legs and give new freedom to people who lose them. It might also help scientists understand how people and animals figure out their own sense of place in space.
“It has been difficult to design robots that can work well when the environment changes or when it’s damaged,” says Olaf Sporns of Indiana University in US. “With this work, we are nearer to solving this problem.”
【小题1】Why do robots easily break down when they are damaged?
A.They cannot repair themselves. |
B.The computer has changed a lot. |
C.They have no computers inside. |
D.The computer cannot work if the robot changes |
A.do housework for humans |
B.keep working after being damaged |
C.remember a lot of information |
D.tell people where it is |
A.sensors | B.robots | C.arms and legs | D.scientists |
A.They can replace the computer when it’s broken. |
B.They can find out where the damage comes from. |
C.They help the computer learn the robot’s condition. |
D.They can send signals to the person who uses the robot. |
When we can see well, we do not think about our eyes often: It is only when we cannot see perfectly that we come to see how important our eyes are.
People who are nearsighted(近视的) can only see things that are very close to their eyes. Many people who do a lot of close work, such as writing and reading, become nearsighted. Then they have to wear glasses in order to see distant things clearly.
People who are farsighted face just the opposite problem. They can see things that are far away, but they have difficulty reading a book if they don't hold it at arm's length. If they want to do much reading, they must get glasses too.
Other people do not see clearly because their eyes are not exactly the right shape. This, too, can be corrected by glasses. Some people's eyes become cloudy because of cataracts (白内障). Long ago these people often became blind. Now, however, it is possible to operate on the cataracts and remove them.
When night falls, colors become fainter(更模糊) to the eyes and finally disappear. After your eyes have grown used to the dark, you can see better if you use the side of your eyes rather than the centers. Sometimes, after dark, you see a small thing to one side of you. It seems to disappear if you turn your head in its direction. This is because when you turn your head, you are looking at the thing too directly. Men on guard duty sometimes think they see something moving to one side of them. When they turn to look straight at it, they cannot see it anymore, and they believe they were mistaken. However, this mistake happens because the center of the eye, which is very sensitive (敏感的) in daylight, is not as sensitive as the sides of the eye after dark,
1.According to the passage, a _______ is more likely to be nearsighted.
A. guard B. doctor C. writer D. painter
2.People who are farsighted _______.
A. cannot do a lot of close work without glasses
B. can only see things that are very close to their eyes
C. have the same problem as the nearsighted people
D. have difficulty reading a book if they hold it at arm's length
3.To see a small thing at night, we need to look _______.
A. with wide open eyes B. with half shut eyes
C. straight at it D. in a slightly different direction