八年级英语uint 3what were you doing When the UFO arrivedPeriod1课件.pptVIP

The alien visited the Museum of flight. The alien bought a souvenir. A UFO landed on Center street. The alien went into a store. An alien got out of the UFO. Look at this picture: * * Unit 3 what were you doing When the UFO arrived? Section A Key phrases: UFO 飞碟，不明飞行物 alien 外星人 bought buy的过去式 land 打开 got get的过去式 take off 起飞 while 当…的时候 Using sentences What ’s this? It’s a UFO. What was it dong? It was landing. What was it dong? It was taking off. land get out of the UFO go into a store visit the Museum take off What was he doing? He was walking down the street and eating. What was she doing? She was shopping. 过去进行时： 过去进行时由“was/were+动词-ing”构成，表示在过去某一时刻或某一时间段正在进行的动作。这一特定的过去时间除有上下文暗示外，一般用时间状语来表示。 一般过去时和过去进行时用法的比较 一般过去时表示在过去某个时间发生过的动作或存在的状态，而过去进行 时表示在过去某一时刻或某一时间段正在进行的动作。 例： David wrote a letter to his friend last night. 大卫昨晚给他的朋友写了封信。（信写完了） David was writing a letter to his friend last night. 大卫昨晚一直给的他朋友写了封信。（信不一定写完了） While the boy was eating and walking down the street, the UFO landed. The girl was shopping when the alien got out. The boy was eating and walking down the street when the UFO landed. While the girl was shopping, the alien got out. When 与 While When引导的时间状语从句既可表示“一段时间”，又可表示“一点时间”因此从句的谓语动词既可是延续性的，也可以是非延续性的，但while引导的时间状语从句只能表示“一段时间”，并且从句中的谓语动词也只能是延续性动词。 例： I hope to see you when (while) I stay in Beijing. 当我到北京时，希望能看到你。 （stay是延续性动词） What was the girl doing when the UFO took off? 当飞碟起飞时，女孩正在做什么？ （take off是非延续性动词，when与while不能互换） Homework 1.站在图书馆前面 2.在理发店理发 3.买纪念品 4.降落在中心街 5.在厨房里煮饭 6.很迟