Not until I began to work__how much time I had wasted．

Not until I began to work__how much time I had wasted．
A、didn't I realize
B、did I realize
C、I didn't realize
D、I realized
【正确答案】：B
【题目解析】：在具有否定意义的词起始的句子中，主句中的主语和谓语要倒装。倒装时，助动词移至主语前面，实意动词仍在主语之后。