5. 下面哪项不是影响种子纯度的因素（） A. 种子加工工艺 B. 种子清理 C. 生长条件是否适宜 D. 生产种子的方式 ...

1. （ ）是分布最广的暖季型草之一，又名百慕大草。 A. 结缕草 B. 天堂草 C. 野牛草 D. 狗牙根 ...

44. We finally abandoned our efforts to save the old building when it became clear that the owner really wanted to ________. A. tear it down B. knock it over C. pull it off D. put it down ...

39. It will take us another five years _______ the construction of all the 121 roads is completed. A. when B. since C. before D. after ...

35. “I can't your rudeness any more，leave the room，”shouted Mary． A. put up to B. put up from C. put up into D. put up with ...

30. The men had to _______ all their strength to lift the tree from the ground. A. exhaust B. reinforce C. harness D. exert ...

26. If you get lost just ask one of the _________ for directions. A. locals B. individuals C. colleagues D. principles ...

22. It rainedfew times during our holiday but on the _______ the weather was fine. A. whole B. rule C. general D. total ...

18. As ______ announced in today's papers. The Shanghai Export Commodities Fair is also open on Sundays. A. being B. is C. to be D. been ...

14. No tricks are allowed ____ the performers are skilled enough to perform safely. A. unless B. if C. once D. after ...