18. In the South such roads are called cow trails because they are ___ by farm equipment and vehicles that plod along at bovine speed . A. seen B. taken C. frequented D. occupied ...

11. Since the mid-1960's considerable research ____ in embryo transplants in many countries . A. has carried out B. was carried out C. carried out D. has been carried out ...

3. The government ____ great importance to intellectual property protection . A. attaches B. puts C. associates D. emphasizes ...

2. The leader was facing threats not only from his former loyalists ,but also his two coalition partners . A. 错误 B. 正确 ...

24. Levels of pesticides and other toxins in fish ____in commercial ponds tend to be much lower than levels in fish caught recreationally. A. raised B. risen C. grown D. produced ...

14. ____ the right answer I would have got full marks in the exam . A. If I have known B. If I'll know C. Had I known D. If was knowing ...

7. The superintendent ordered that the area ___. A. evacuated B. be evacuated C. being evacuated D. to be evacuated ...

6. There was a pile of assorted books in the corner . A. 错误 B. 正确 ...

1. Some people become very possessive about little things . A. 错误 B. 正确 ...

24. He spoke so ____ that even his opponents were won over by his arguments . A. frankly B. emphatically C. determinedly D. convincingly ...