问题补充:
When the millionaire was young, he was very poor. Only by doing parttime jobs during the summer holiday afford to pay his college fees.
A. he could
B. could he
C. can he
D. he can
答案:
A. he could
(答案→)B. could he
C. can he
D. he can
解析:选B考查倒装和时态。句意:当这位百万富翁年轻的时候,他非常穷。只有在暑假做兼职工作他才能付得起大学的学费。“only+状语”置于句首时,句子应用部分倒装,此处说的是过去的事情,故选B。