英语外研版选修7 Module 4 Music Born in America-Grammar课件(

The moment I get the money I'll send the ticket. I was just getting into the bath when the telephone rang. He gets more attractive as he gets older. Whenever I go there they seem to be in bed. I've been very busy since I came back from holiday. parts of these sentences indicate the “time”.

状语从句状语从句在主从复合句中修饰主句中的 动词，形容词或副词，按意义可分为时 间、地点、原因、目的、结果、条件、 方式、比较、让步等状语从句。从句可 放在句首，也可放在句末。放在句首时， 从句后面常用一个逗号，放在句末时， 从句前一般不用逗号。本模块着重讲解 时间状语从句。

时间状语从句： 引导时间状语从句的从属连词有：when, while, as, whenever, before, after, since, till, until, as soon as, once,the moment, immediately, no sooner…than, hardly…when, by the time, every time, last time…等。

(1)when, as, while (从属连词) when既可引导持续性动作，又可引导短 暂性动作。它可以表示主句的动作和从句 的动作同时发生，或从句的动作发生在主 句动作之前。如： When I was a boy, I used to go to the seashore on Sundays.(同时) When the lesson was over, we began our writing.(从句动作在前)

as引导持续性动作，侧重主句和从句的动 作同时发生。 He hurried home, looking behind as he went. I saw your sister as she was getting on the bus yesterday. He sang as he walked.

while指的是“在某一时间里”, “在……期间”,从句里的动作必须是持 续性的，它也强调主句和从句动作的同时 发生，往往侧重主句和从句动作的对比。 如：While he was in London, he studied music. While we were watching TV, he was writing a composition.

当when, as, while表示“在…一段时间 里”,主从句的动作同时发生时，可以 换用。如： While (When/As) we were discussing, Mr. Smith came in.

*when 可表示“如果”。如：

Don’t be afraid of asking for help_____ it is needed. (2003全国) A. UnlessC. although

B. sinceD. when

*while可表示“虽然，尽管”。如： 1)____ modeling business is by no means easy to get into, the good model will always be in demand.(2004浙江) A. While B. Since C. As D. If

* _____ I accept that he is not perfect, I do actually like the person. (2004江 苏)

A. WhileC. Before

B. SinceD. Unless

when和while(并列连词) while表示对 照的意思；when 表示“这时，突然……”1) I do every single bit of housework____ my husband Bob just does the dishes now and then.(2004广西) A. since B. while C. when D. as 2) He was about to tell me the secret____ someone patted him on the shoulder. (2002上海) A. as B. until C. while D. when

3) We were swimming in the lake ____ suddenly the storm started.(2004北京春) A. when B. while C. until D. before 4) Jasmine was holidaying with her

family in a wildlife park____she was bitten on the leg by a lion. (2004上海) A. when B. while C. since D. before

(2)till和until

①如果主句谓语动词是持续动词， 通常用肯定式的主句，表示“直 到……为止”。如：I worked till (until) he came back.

1) A good storyteller must be able to hold his listeners’ curiosity _____ he reaches the end of the story.(2003上海) A. when B. unless C. after D. until 2) We were told that we should follow the main road ___we reached the central railway station.(2004辽宁) A. whenever B. until C. while D. wherever