完形填空
Birds can see colours, just as people do. Birds need to see colours when they fly. Colours help them know 1 the place is and what it is like. This way, they can catch flying things in the air or land on something they think 2.
Birds can “tell” the 3 between colours. But for some other animals, such as wolves, the world looks like a black and 4 photo. Wolves look for food mainly by smelling and 5. They can hear 6 when the animals they hunt move. But other animals seem to know this. For example, a rabbit will stop moving when it finds there is something 7. Then the wolves 8 not find it at all.
Some birds’ eyesight is 9 than people’s. They can see small insects 10 they fly in the sky. They are able to 11 colours, so they can get food easily and 12 if there are other animals that are dangerous to them.
Scientists do lots of 13 to learn more about wildlife’s senses. The 14 they get helps us protect living things on Earth. Their research also helps people make bionic (仿生的) 15. For example, people study how bats sense things and invent sensors.
() 1. A. how soon B. how far C. how long D. how often
() 2. A. near B. safe C. high D. low
() 3. A. differences B. sizes C. kinds D. similarities
() 4. A. grey B. red C. white D. blue
() 5. A. shouting B. listening C. eating D. moving
() 6. A. badly B. slowly C. safely D. clearly
() 7. A. dangerous B. safe C. slow D. fast
() 8. A. should B. must C. may D. need
() 9. A. bigger B. smaller C. worse D. better
()10. A. when B. why C. where D. how
()11. A. paint B. see C. read D. watch
()12. A. give out B. find out C. look out D. take out
()13. A. homework B. sport C. research D. writing
()14. A. questions B. mistakes C. results D. habits
()15. A. products B. plans C. secrets D. birds

1. B
2. B
3. A
4. C
5. B
6. D
7. A
8. C
9. D
10. A
11. B
12. B
13. C
14. C
15. A