—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
网友回答
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”。