25.　 C

24.　 D

23.　 C

22.　 B

21.　 C　 句中有連詞that和謂語must be stimulated，缺少一個(gè)謂語動(dòng)詞，排除A,D，該句譯成漢語是“有。。。的證據(jù)”,而不是“它是。。。的證據(jù)”所以排除B.

20.　 D on which to base his arguments in favor of the new theory = The professor will base his arguments in favor of the new theory on sufficient grounds.

19.　 B

18.　 C 該題空格處缺少的是連詞，且在從句中作主語，所以排除A,D; that在名詞性從句中只起連接作用。

17.　 A

16.　 D the results of which 等于whose results，是非限制性定語從句。