—Tom,youlooktiredthismorning.What’swrong? —Iwassobusyth...

问题详情：

—Tom, you look tired this morning. What’s wrong?

  —I was so busy that I didn’t go to bed _____ 12 o’clock last night.

  A. until           B. when         C. though            D. unless

【回答】

A

知识点：相似 相近词比较

题型：选择题