In this firm, it is necessary that whoever ______ recently come here _____ this kind of test.
He had little idea that it was getting so serious, __________?
—___________ makes her different from the other students?—Diligence, I think.
Not until I went through his paper _________ what rapid progress he had made in writing.
I don’t remember how many years ago _____ I was taken to Beijing for the first time.
Never in my wildest dreams ____ these people are living in such poor conditions.