題目：

41. Your trousers ____dirty， you must have _____washed.

??? A.???? is； it?????? B. are； it?????? C. are； them???? D. is； them

42. Where ____rubbish， there are flies.
??? A.???? there are??? B. there is????? C. is???????? D. there has?

43. The Olympic Games ____held every ____years.
??? A.???? is； four???? B. are； four???? C. is； five???? D. are； five

44. Many a man _____ come to help us.
??? A. have??? B. has???? C. is???? D. are

45. He is the only one of the students who _____elected.
??? A. are???? B. have????? C. has??? D. is

?46. Three-fourths of the homework _____today.
??? A.???? has finished???????? B. has been finished
??? C. have finished???????????????? D. have been finished

47. Those who ____ in ____compositions， please hand them in this afternoon
? ? A.???? hasn‘t handed； his??? B. haven’t handed； their
? ? handed； their????? D. have handed； his

48. Jane is one of the best students in her class who _____by their teacher.
??? A.???? are praised??? B. is praised??? C. praised??? D. praising

49. The whole class _____the teacher attentively.
??? A.???? are listening to?????? B. is listening to
??? C. are listening???????????? D. is listening

50. The United States of America _____one of the most developed countries in the world.
??? A. is????? B. are???? C. was???? D. were

【答案解析】

?41-45 CBBBD ??46-50 BBAAA