第三节 完形填空: (共10小题;每小题2分,满分20分) 根据短文内容，从各题所给的 A、B、C、D 四个选项中，选出可以填入空白处的最佳选项。

Although they live in the 　41 　, whales and dolphins are mammals .there are many types of whales.Some whales eat krill (磷虾) and plankton. Some eat fish. The sperm whales love to eat giant squid(乌贼). Killer whales eat fish, and　 　42 　even eat seals (海豹) and other whales.The blue is the largest animal in the world. It can grow up to 120 feet long, and can weigh up to 170 tons.

　　 Since whales and dolphins are mammals, they cannot breathe under water.They must come to the surface to breathe air. They breathe through a blowhole, or nostrils,on the top of their head . 43 　are born under water and must be pushed to the surface by the mother, so that they can take a breath.Whales and dolphins also look different from many other mammals because they don’t have fur,although they do have a sparse (稀少的) covering of 　44　 .

Their circulatory and respiratory systems (循环和呼吸系统) have　 45 　to living in water. Whales and dolphins can dive deep in the water on a single breath.

　　 Whales and dolphins also have a 46　 developed brain. They are considered to be very 　47 . 　　

　　 Dolphins as well as some whales, can use echolocation (回声定位法) to find food and to identify objects 　48 　them. They make　 　　49　 　　clicking and squeaking sounds that bounce off (从……弹回) objects and echo (发出回声) back to the dolphin. This echo　 　50 　the dolphin of the nearby object.

41.A. shore　　　　　　 　B. water　　　　　 C. desert　　　　　 D. zoo

42.A. never　　　　　　 　B. seldom　　　　 　C. sometimes　　 　D. some times

43.A. Babies　　　　　 　B. Animals　　　 　C. Fathers　　　　 　D. Dolphins

44. A. fur　　　　　　　 B. hair　　　　　 C. skin　　　　　 　D. organ

45. A. been　　　　　　 　B. focused　　　 C, admitted　　　 D. adapted

46. A. high　　　　　　 　B. special　　　 C. highly　　　　 D. quickly

47. A. intelligent　 　　B. pretty　　　　 C. lazy　　　　　 D. excellent

48. A. behind　　　　　 　B. around　　　　 C. before　　　　 D. far away

49. A. much　　　　　　 　B. busy　　　　　 C. noisy　　　　　 D. loud

50. A. asks　　　　　　 B. informs　　　 C. warns　　　　 　D. argues

30. The thought of going back home was _____kept him happy while he was working abroad.

　A. that　　 B. all that　 C. all what　　 D. which..

29. The engineer _____my father works is from America.

　A. with who　　 B. with whom　　 C. on whom　　 D. with which

28. We are talking about the piano and the pianist ______were in the concert we attended last night.

　A. who　　 B. which　 C. what　　 D. that

27. The building ______ will be completed in a month. It will be our lab building.

　A. to paint　　 B. to have painted　　 C. painted　　 D. being painting

26. I can’t stand _____with Jane in the same office. She just refuses ____talking while she work.

　A. working; stopping　　 B. to work; stopping　 C. working; to stop　 D. to work; to stop