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.

A．until

B．when

C．though

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。