B did i realize
这是 not ...until..句型 not until 置前 主句 要部分倒装 也就是用疑问句语序
希望 记住 下面 三个句型
正常 i didn't realize how much time i had wasted until i began to work.
倒装 not until i began to work did i realize how much time i had wasted.
强调 it was not until i began to work that i realized how much time i had wasted.
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