—Why does Sara know so much about Angkor Wat?—She there or she may have read about it.

问题补充：

—Why does Sara know so much about Angkor Wat?

—She there,or she may have read about it.

A. must have been

B. shouldn’t have been

C. may have been

D. can’t have been

答案：

A. must have been

B. shouldn’t have been

(答案→)C. may have been

D. can’t have been

解析：此题考查情态动词表推测的用法。由后面or...来判断，说话人对此事不是很有把握，故用may have done表示对过去情况不太肯定的推测，意为“或许做了某事”。must have done用于肯定句，表示对过去情况肯定的推测，意为“一定发生了某事”。