问题补充:
—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
答案:
A. may go through
B. might go through
C. ought to have gone through
(答案→)D. must have gone through
解析:该题考查情态动词的用法。情态动词+have done表示对过去的推测。句意为:“为研究野生动物,这个女生物学家在回来前在非洲待了。”“哦!她一定克服了许多困难。”