Not until I began to work ________ how much time I had wasted.
A.didn't I realizeB.did I realizeC.I didn't realizeD.I realize在线课程B
这是一个倒装句型。带有否定意义的词或短语放在句首，语序需要部分倒装。常见的词语有not，never，seldom，scarcely，barely，little，at no time，not only，not once，under，no condition，hardly…when，no sooner…than等。这里not until是否定副词，因此选B。