until、 before

选 until

Could you wait until I get the book back.
意思是：你能等我一下直到我把书取回来吗？

before的用法：
before可以作为连词，引导时间状语从句。它的用法灵活、译法多变。
1．before作“还没来的及……就……”，“未……就……”，“……就……”或“……便…”解时，强调主句或从句谓语动词表示的动作发生得过早或过快。例如：
He announced the ending of the meeting before I could get in a word.
没等我插上一句话，他就宣布散会了。
Someone called me up in the middle of the night, but they hung up before I could answer the phone.
有人半夜给我电话，但我还未来的及接他就把电话挂了。

[典型例题（加下划线的为正确答案）
① －Why didn’t you tell me him about the meeting?
－He rushed out of the room ____ I could say a word.
A. before B. until C. when D. after
② －He made a mistake, but then he corrected the situation ____ it got worse.
A. until B. when C. before D. as

2．before作“……才…”解时，强调从句谓语动词表示的动作发生得太慢或太晚。例如：
The bus driver almost knocked me down before he saw me.
那位公交车司机差一点把我撞倒，他才看见我。
The fire lasted about four hours before the firefighters were able to con