通过高考题精讲 once 引导的状语从句
once引导的状语从句可以表示时间和条件的意思。
逻辑上，从句和主句有很强的顺承关系。
Once+从句，主句往往用一般将来时。
_____the damage is done, it will take many years for the farmland to recover. (北京卷)
A. Untill B. Unless C. Once D. Although
解析：本题考查状语从句；选择C；once表示时间和条件。
句意：一旦破坏造成了，那么。。。。
_____the damage is done, it will take many years for the farmland to recover. (北京卷)
A. Untill B. Unless C. Once D. Although
其他选项的意思不对。
9. I believe you will have a wonderful time here you get to know everyone else. (陕西卷)
A. thought B. as if C. once D. so that
解析：本题考查状语从句；选择C；once表示时间和条件。
句意：一旦你了解了这里其他每个人，我相信。。。。。。
I believe you will have a wonderful time here you get to know everyone else. (陕西卷)
A. thought B. as if C. once D. so that
小练习：
You will be successful in the interview________ you have confidence.
A.before B.once C.until D.though
解析：B
You will be successful in the interview_____ you have confidence.
A.before 时间关系反了，after反而更好
B.once
C.until 语义不对，成功持续到有自信
D.though 语义不对，虽然有自信 但不成功
