时间:2020-9-23 作者:admin


  It was not long before…(过去)没过多久就……

  It was not long before he returned to Beijing. 不久他就回到北京。

  需要特别注意,该句型可以进行创新,可将否定句改为肯定句(It was long before…过了很久才……)或将一般过去时改为一般将来时(It will not be long before…要不了多久就……;It will be long before…要过很久才……)。before在这些句型中均引导时间状语从句, long这个抽象的时间也可改为years, weeks, days等具体表时间的词。

  It was long before he married Wei Fang. 过了很久他才娶魏芳。

  It will be long before he goes abroad. 要过很久他才出国。

  Will it be years before he goes to school? 要过好几年他才能上学吗?


  It ________ long before we ________ the result of the experiment.

  A. will not be…will know B. is…will know C. will not be…know D. is…know

  【析】正确答案为C。该句面意思为:在我们知道实验结果之前不会过很长一段时间,也就是不会过很长一段时间我们就会知道实验结果。应使用It was not long before的创新句型It will not be long before,before引导时间状语从句时,从句应用一般现在时代替一般将来时。

  Scientists say it may be five or six years ________ it is possible to test this medicine on human patients.

  A. since B. after C. before D. when

  【析】正确答案为C。该句型也是It was not long before的创新句型。



  before作为连词时的基本意义是“在……之前”,用于表示时间或顺序。如:Turn the light off before you sleep. (睡前先把灯熄掉。) Think before you speak. (说话之前,应先想清楚。) 但在不同的语境中before有不同的意义:

  1. before表示“不等……就……”、“尚未……就……”

  例1: —Why didn’t you tell him about the meeting? (2006年四川)

  —He rushed out of the room I could say a word.

  A. before B. until C. when D. after

  解析: 答案为A。题中before意为“不等……就”、“尚未……就……”,它表示从句的动作尚未来得及发生,主句的动作已发生或完成。全句句意为:我还没来得及说他就冲出了房间。又如:

  Before I could get in a word, he had measured me. 我还没有来得及插上话,他就给我量好了尺寸。

  The phone stopped ringing before I answered it. 我还没有来得及接,电话就挂了。

  2. before表示“不知不觉,还没弄清就……”(常用于before sb. know/realize…)

  例2: Several weeks had gone by I realized the painting was missing. (2004全国)

  A. as B. before C. since D. when

  解析: 此题最易错选C或D项,而正确答案为B。用since则时间延续到了现在,在时间上与had gone矛盾;用when则无法强调时间流逝的不知不觉性。又如:

  Time passed quickly and three months went by before I knew it. 时间飞快地流逝,不知不觉3个月过去了。

  3. before表示“以免,不然”

  例3: It’s cloudy. Take an umbrella you regret it.

  A. but B. and C. after D. before

  解析: and及but表示并列关系,不合语境;after意为“在……之后”,不合常识,应是在下雨前带伞;before在此处意为“以免你后悔”。before作此意义的用法的例子不少,又如:

  Put that away before it gets broken. 把它收好,以免砸了。

  Do it before you forget. 尽早动手,不然忘了。

  4. before用于it was / will be + 时间 + before … 句型中。

  例4: It won’t be long you regret what you have done.

  A. after B. before C. since D. until

  解析: It was / will be + 时间 + before … 表示“过了多久才…(强调时间的长)”,在否定句中则表示“没过多久就…(强调时间的短)”。例如:

  It will be two years before we meet again.我们要过两年才能见面。

  It wasn’t long before he married again. 不久他就又结婚了。

  We didn’t wait long before he came back. 我们没等多久他就回来了。

  5. before表示“与其……宁可……,比……优先”(用于表优先顺序)

  例5: They would fight to death they surrendered(投降).

  A. before B. after C. since D. because

  解析: 答案为A。before引导的从句在与will, would连用时,有“宁愿……也不”的含义。before即使是作介词用也有此意义。例如:

  True men choose death before dishonor. 大丈夫宁可杀不可辱。

  I’d die before I apologize to them! 我宁死也不愿向他们道歉!

  We will die before we give in. 我们宁死不屈。

  6. before表示“……才”(强调从句动作发生得晚或慢)

  例6: They sailed along the Pacific Ocean for two weeks they arrived home.

  A. since B. when C. before D. after

  解析: 此题正确答案为C。全句句意为:“他们在太平洋航行了两个星期才回到家。”强调从句动作比主句动作发生晚。又如:

  I thought carefully about it before I made a decision. 我经过再三考虑才决定。

  It may be many years before the situation improves. 或许要过很多年这种状况才能得到改善。


  Don’t be afraid of asking for help ____ it is needed.

  A. unless B. since C. although D. when


  下面我们来归纳一下when 的用法:


  I don’t know when he died.


  Since when has he been missing?



  He came at a time when we needed help.


  We’ll never forget the day when we joined the Party.




  It was raining when we arrived.


  When I was a boy, I used to go to the Western Hills on Sundays.


  It is cold when (whenever) it snows.


  He joined the PLA when (as soon as) he returned home.



  How can they learn anything when they spend all their spare time watching television?


  They have only three copies when we need five.


  The waitress brought me coffee when I asked for tea.


  ③ 意为“如果,要是”。如:

  You shall have the apple when you say “Please”.


  He will likely recover when he undergoes the operation.


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