Question

Never before ________ buying a computer, but now it seems a necessity in my everyday life

1. A.
   did I think of
2. B.
   have I thought of
3. C.
   I thought of
4. D.
   I have thought of

Answer 1

B
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。