状语从句种类从属连词例句说明as和before

状语从句种类从属连词例句说明as和before
as
He hurried home, looking behind as he went.
他赶快回家，不时地一边走一边向后看。 as引导持续性动作，强调主句和从句的动作同时发生
As I get older, I get more optimistic. 两种正在发展或变化的情况，有“随着”的意思，表时间的推移。
He hurried home, looking behind as he went.
他匆忙地回家，边走边往后看。一边……一边……
As he was going out, it began to rain.当他出去的时候，就开始下雨了。强调两个动作紧接着发生。
As a boy(When he was a boy), he was hopeless at maths.
当他还是孩子时，就已对数学失去了希望。 as+名词，相当于时间状语从句
初二下册英语电子课本
 速记英语单词的方法
 高中英语教材

before
Be a pupil before you become a teacher.先做学生，再做先生。
A. We waited a long time before he came out. 我们等了很长时间他才出来。
B. We hadn’t waited long before he came out.我们没等多久他就出来了。
C．He died before he wrote a will.他还没来得及写遗嘱就死了。
The sun had set before we knew it.不知不觉的太阳已经落山了。
Leave me before I changed my mind.趁我还没有改变主意，快离开我。
I’d die before I apologized to them.我宁死也不向他们道歉。
Get out before I call the police.滚开，否则我叫警察了。往往表示主句的动作先于从句的动作发生，“在……之前”，
A.“ ……才”（强调主句所表达的时间、举例很长或花费的力气很大。）
B.“……就”（强调主句所表达的时间、举例短或花费的力气很大。）
C．“还没有……”“免得”“不知不觉”“宁可、宁愿”“否则，要不然”
It will be five years before he returns to his homeland. 再过五年他才能回国。
It won’t be long before we meet again.过不了多久我们就会再见面的。 It+（not）be+some time+before从句。肯定句中，“多长时间之后才”；否定句中，“用不了多长时间就”
after He arrived after the game started.比赛开始后，他到了。

1. “I still haven’t thanked Aunt Lucy for her present.” “It’s time you _____.”
A. do B. did C. had D. would
2. If I hadn’t been lucky enough to meet you. I really _____ what I would have done.
A. don’t know B. hadn’t known
C. wasn’t knowing D. wouldn’t know
3. “I’ve told everyone about it.” “Oh, I’d rather you _____.”
A. don’t B. hadn’t
C. couldn’t D. wouldn’t
4. It has been raining for a day, but eventhough it hadn’t rained, we _____ there by tomorrow.
A. can’t get B. won’t get
C. hadn’t got D. wouldn’t get
5. “Do you know his address ?” “No, I also wish I _____ where he _____.”
A. knew, live B. knew, lives
C. know, lives D. know, lived
6. “Isn’t it about time you _____ to do morning exercises?” “Yes, it is. Would you like to join us?”
A. begin B. have begun
C. began D. had begun
7. It is hard for me to imagine what I would be doing today if I ____ in love, at the age of seven, with the Melinda Cox Library in my hometown.
A. wouldn’t have fallen B. had not fallen
C. should fall D. were to fall
8. He hesitated for a moment before kicking the ball, otherwise he ____ a goal.
A. had scored B. scored
C. would score D. would have scored
9. If only he _______ quietly as the doctor instructed, he would not suffer so much now.
A. lies B. lay
C. had lain D. should lie
10. Without the air to hold some of the sun’sheat, the earth at night ____ for us to live.
A. would be freezing cold B. will be freezing coldly
C. would be frozen cold D. can freeze coldly
1.
【解析】选B.It’s time you did 为 It’s time you thanked Aunt Lucy for her present 之略。按照英语语法，it’s time 后从句通常要用过去式。
2.
【解析】选A.虽然前有虚拟条件句, 后有使用了虚拟语气的宾语，但 I don’t know 却宜用一般现在时，因为 I don’t know 表述的是现在的真实情况，句意为“我要不是有幸遇到你，我真不知(指现在不知)我会做出什么蠢事来”。
3.
【解析】选B.I’d rather 后接从句时，从句谓语的时态规律是：用过去式表示现在或将来，用过去完成式表示过去。
4.
【解析】选A.we can’t get there by tomorrow 为客观事实，故宜用陈述语气。
5.
【解析】选B.第一空填 knew，因为 I wish 后的宾语从句要用虚拟语气(即用过去式表示现在的想法);第二空要填lives，即用陈述语气，因为 where he lives 是一个客观事实，而不是 I wish 的内容。
6.
【解析】选C.It’s time… / It’s high time… / It’s about time… 等后接从句时，从句谓语通常用过去式。
7.
【解析】选 B.此题涉及错综时间虚拟条件句，主句与现在事实相反，条件句与过去事实相反。句意为：要不是在七岁时就迷上了 Melinda Cox 图书馆，我真不能想像我如今会在做什么。
8.
【解析】8. 选 D.这是otherwis e 引出的含蓄虚拟语气，再根据前面的 hesi tated 可进一步知道这是与过去事实相反的虚拟语气，由此可推知答案选 D.
9.
【解析】选 C.if only意为“要是……就好了”，其后的句子谓语要用虚拟语气，同时根据 as the doctor instructed 中的过去时态可知从句是与过去事实相反，故选 C.
10.
【解析】选 A.without 引出的介词短语为一个与现在事实相反的含蓄条件句。
【答案】C