问题
选择题
—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
D
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13年。”“哦！她一定克服了许多困难。”