问题补充:
Never before buying a computer, but now it seems a necessity in my everyday life.
A. did I think of
B. have I thought of
C. I thought of
D. I have thought of
答案:
A. did I think of
(答案→)B. have I thought of
C. I thought of
D. I have thought of
解析:考查部分倒装。Never是表否定意义的词,放在句首时,句子谓语要部分倒装,排除C,D;根据never和before,可知句子应该用现在完成时态,所以选B。