问题
选择题
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
答案：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。