1．—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
解析：
go through意为“经历（痛苦的事），”从第一句可以看出现在谈论过去的事情，ought to have done表示“本该做却没有做的事情”，因此选must have done，表示“她一定经历了很多困境。”
答案：D
2．______ about wild plants that they decided to make a trip to Madagascar for further research.
A．So curious the couple was
B．So curious were the couple
C．How curious the couple were
D．The couple was such curious
解析：“副词so+ adj.”位于句首，要用倒装。
答案：B
3．Never before _______ in greater need of modern public transport than it is today.
A．has this city been B．this city has been
C．was this city D．this city was
解析：否定词never位于句首，后面的句子要使用部分倒装。
答案：A
