The past 30 years has the great changes that have taken place in China.A. seenB. noticedC

问题补充：

The past 30 years has the great changes that have taken place in China.

A. seen

B. noticed

C. watched

D. looked

答案：

(答案→)A. seen

B. noticed

C. watched

D. looked

解析：考查动词：A. seen 看见，见证B. noticed注意到C. watched观察D. looked看，句意：过去30年已经见证的中国的巨大变化。选A。