While/ when 专项训练
When和While的区别
①when是at or during the time that,既指时间点,也可指一段时间,while是during the time that,只指一段时间,因此when引导的时间状语从句中的动词可以是终止性动词,也可以是延续性动词,而while从句中的动词必须是延续性动词.
②when 说明从句的动作和主句的动作可以是同时,也可以是先后发生；while 则强调主句的动作在从句动作的发生的过程中或主从句两个动作同时发生.
③由when引导的时间状语从句,主句用过去进行时,从句应用一般过去时；如果从句和主句的动作同时发生,两句都用过去进行时的时候,多用while引导,如：
a.When the teacher came in,we were talking.当此句改变主从句的位置时,则为：While we were talking,the teacher came in. b.They were singing while we were dancing. ④when和while 还可作并列连词.when表示“在那时”；while表示“而,却”,表对照关系.如：a.The children were running to move the bag of rice when they heard the sound of a motor bike.孩子们正要跑过去搬开那袋米,这时他们听到了摩托车的声音. b.He is strong while his brother is weak. 他长得很结实,而他弟弟却很瘦弱. 一、用when或者while填空
1.______ Maria was talking on the phone, her sister walked in. 2.______ we visited the school, the children were playing games. 3.______ Sally was at the doctor’s, I was going to class. 4.______ I saw Kangkang, he was wearing a green shirt. 5.______ Allen was cleaning his room, the phone rang. 6.______ Rita found her pet dog; it was wearing a little coat. 7. He was driving along ________ suddenly a woman appeared. 8. _____ Jake was waiting at the door, an old woman called to him. 9. He was reading a book ______suddenly the telephone rang. 10. ______ it began to rain, they were playing chess.
11. She saw a taxi coming ______ the woman was waiting under the tree. 12. The elephant was in the museum, _______I called the police.
13. The boy was walking down the street________ a UFO landed（着陆）. 14. I was cleaning my room__________ the fire broke out.
15. Linda shouted his name,________ some people looked at her. 二、用所给动词适当形式填空
16. While Jack __________ (look) for customers（顾客）, he _______ (see) a woman. 17. They __________ (play) football on the playground when it _____ (begin) to rain. 18. A strange box ________ (arrive) while we _________ (talk).
29. John ____________ (sleep) when someone __________ (clean) his car. 20. Father (sleep) when I (get) up yesterday morning.
21. Grandma (cook) breakfast while I (wash) my face this morning. 22. Mother (clean) the floor when I (leave) home.
23. I (read) a history book when someone (knock) at the door. 24. Mary and Alice are busy (do) their homework. 25. The teacher asked us (keep) the windows closed.