Question

---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．

1. A.
   until
2. B.
   when
3. C.
   though
4. D.
   unless

Answer 1

A
考查点：连词辨析。解题思路：根据句意：汤姆，今天上午你看起来很累。怎么了？我非常忙以至于昨天晚上12点才上床睡觉。not…until…表示“直到……时候才……”。故选A。