---- The woman biologist stayed in Africa studying wild animals for 13 years before she returned.
---- Oh, dear! She a lot of difficulties!
A. may go through
B. might go through
C. ought to have gone through
D. must have gone through
网友回答
A. may go through
B. might go through
C. ought to have gone through
(答案→)D. must have gone through
解析：检查考生对情态动词表示判断的掌握和运用能力。首先，对过去发生事情的判断用情态动词+完成形式；其次，ought to have done 表示“本应该……”，即事情没有做，所以不符合语境。must have done 表示“肯定……”。