三、重点语法
1．before，after，when和while引导的时间状语从句before，after，when和while用作连词时可以引导时间状语从句。
(1) before意为“在……之前”，表示主句动作发生在从句动作之前。如：
He always clears up his bedroom before he goes out.
他在出去之前总要先把房间收拾好。
(2) after意为“在……之后”，表示主句动作发生在从句动作之后。如：
He always goes out after he clears up his bedroom
他总是在把房间收拾好之后出去。
(3) when意为“当……时”，表示主句动作发生的特定时间。如：
She smiles when you praise her.
每当你夸她的时候她就笑。
when引导的从句的谓语动词可以是延续性的，也可以是瞬间性的。
(4) while意为“与……同时”，强调主句动作和从句动作是同时发生的。如：
She looked after her sister's baby while her sister was ill.
她姐姐生病时，她照顾她姐姐的宝宝。
while引导的从句的谓语动词必须是延续性的。
2．since，till和until引导的时间状语从句since，till和until用作连词时，也可以引导时间状语从句。
(1) since意为“自从……以来”。通常情况下，从句的谓语动词用一般过去时，而主句的谓语动词用现在完成时。如：
It has been two years since they moved here.
自从他们搬到这儿已经两年了。
since引导的从句的谓语动词可以是延续性动词，也可以是瞬间性动词。
(2) till和until意为“到……为止”，通常两者可通用。until可以放在句首或句中，而till不可以放在句首。如：
I'll wait here till/until my father comes back.
我要在这里一直等到爸爸回来。
如果主句的谓语动词是瞬间性动词，必须用否定形式，即“not…until”结构，意为“直到……才（开始）”。如：
I didn't go to bed until I finished my homework last night．
昨晚我直到完成作业才睡觉。
3．as soon as和whenever引导的时间状语从句
(1) as soon as意为“一……就……”。如：
The bus began to go as soon as I got on it.
我一上车，车就开动了。
(2) whenever意为“每当；无论何时”。如：
Whenever we're in trouble, they come to help us.
每当我们遇到麻烦的时候，他们就来帮助我们。
考点精练
( )1. (2014 .梅州)1 was watching TV _______ my brother was writing an email at home at this time last night.
A as soon as B. after C. until D. while
( )2. (2014 .济宁)Laura opened the door and rushed into the rain _______ I could stop her.
A until B. after C. before D. unless
( )3. (2014 .温州)- Excuse me. Is it my turn now?
- Not yet. Please wait on the chair _______ your name is called.
A and B．until C．although D．since
( )4. (2014．黄冈) -I can hardly believe my eyes. Is that you, Lucy?
- Yes. It has been almost 20 years_______ we were together.
A．since B. before C after D．until
( )5. (2014．菏泽)When will you return the book to me?
- I'll give it to you_______ I finish it.
A. once B．until C as soon as D．unless
( )6. (2014．成都) _______ I am in trouble, my classmates will help me out.
A．Before B．Whenever C Although
二、根据句意及中文提示完成单词
1. Keep trying and never give up. I believe you will _______（成功）one day.
2. The Red Army were_______（被迫）to have the Long March
3. She broke the_______（记录）of high jump in the sports meeting.
三、根据汉语提示完成句子
1．那时我们简直无法理解他脑子里在想些什么。
We could hardly understand what was_______ at that time
2．这些队伍将要参加奥运会的选拔赛。
These teams will_______ the Olympic Games.
3．你是怎样使吴老师改变主意的？
How did you get Mr Wu_________？
4．据说MH370航班共有239人不幸失去生命，包括154名中国人。
It's said that all 239 people in the flight of MH370 _______ their_______, including 154 Chinese.