完形填空（共20小题；每小题1分，满分20分）
请认真阅读下面短文，从短文后各题所给的A、B、C、D四个选项中，选出最佳选项，并在答题卡上将该项涂黑。
Most people think of birds as feathered animals that fly. Scientists, 36 , do not define (给…下定义) birds as animals that fly, because some birds do not. Of the 10,000 or so species of birds, 46 cannot 37 . Flight plays a key role in 38 for most birds. It allows them to find food over a 39 area and to get away from enemies. Ancestors of flightless birds may have 40 their ability to fly because they had no regular predators (捕食者) or did not need to fly to find food. Rather than fly, some of these birds developed other 41 to catch food and avoid enemies. Two examples of 42 birds are penguins and ostriches.
43 birds that fly, penguins do not have wide wings or large feathers. In order to catch the fish they feed on, penguins use their powerful wings to swim 44 . And when they swim, they look as if they are flying through the water. The 45 of penguins’ bodies makes it possible for them to dive deep underwater, 46 their thick feathers protect them from the cold.
Ostriches are known for their long legs, long necks, and large size. To 47 themselves, they stay in groups and use their excellent sight and hearing to 48 enemies. As soon as 49 approaches, they can run at a speed of more than 65 kilometers per hour to 50 . In addition to using their strong legs to run, they can kick powerfully.
Not all flightless birds have been 51 in protecting themselves. Flightless birds on some islands had no enemies until people 52 . These birds were hunted and easily caught by people and the animals 53 by people. Human land development has 54 the habitats of some birds. A number of flightless birds 55 because they were unable to adapt to new conditions and new enemies.
1. A．thus B．however C．therefore D．otherwise
2. A．stand B．fly C．hear D．sing
3. A．growth B．communication C．health D．survival
4. A．wide B．familiar C．crowded D．special
5. A．developed B．improved C．lost D．proved
6. A．parts B．habits C．ways D．tools
7. A．wild B．interesting C．rare D．flightless
8. A．Instead of B．Because of C．Besides D．Unlike
9. A．quickly B．carefully C．differently D．gradually
10. A．shape B．color C．bone D．skin
11. A．if B．and C．but D．so
12. A．help B．feed C．protect D．hide
13. A．kill B．notice C．confuse D．frighten
14. A．dawn B．darkness C．danger D．food
15. A．look B．escape C．move D．fight
16. A．successful B．natural C．unusual D．positive
17. A．realized B．acted C．stopped D．arrived
18. A．brought B．found C．bought D．hunted
19. A．provided B．formed C．destroyed D．controlled
20. A．flew away B．watched out C．gave away D．died out
– Shall we invite Jim and his sister to our party?
– ______. They’ll have fun with us, I think.
A．No way! B．Why not?
C．Good for you! D．What for?
If penicillin had not been available, many people _____ from sickness or even small wounds.
A．would die B．would have died
C．will have died D．might die
The Japanese government stubbornly claimed the ownership of Diao Yu Islands belonging to China, ______ greatly hurt the friendship between the two peoples.
A．that B．what C．which D．it
– Shall we go out for lunch?
– Don’t disturb me. I ______ the letters all morning and ______ six so far.
A．write; wrote
B．wrote; have written
C．was writing; wrote
D．have been writing; have written
A lot of people ______ the theory that acupuncture can produce chemicals in the body which reduce pain.
A．correspond to B．relate to
C．subscribe to D．refer to
