What were you doing when the UFO arrived
八年级下英语学案第13课时
【课题】：unit 3 section a (1a-2c)
【励志小木屋】：i don’t think much of a man who is not wiser today he was yesterday如果一个人今天没有比昨天变得更聪明，那我是不会看重他的。
【预习目标】：1.识记p18-19 单词、短语 2.理解一般过去时与过去进行时的区别。3.理解when, while 引导的时间状语从句
【预习重难点】：重难点：1.when, while引导的时间状语从句。
2.过去进行时。
一. 自主预习
（一） 预习任务
1. 写出下列单词、短语： 在图书馆前面_________ 做饭_________ 理发_______ 睡过头________ 在浴室_________ get out of the shower___________ land on________ take off_______
barber shop_________
2.英汉互译：1). they wrote letters to their friends last night .
2). they were writing letters to their friends last night .
3).昨天我们上了一节英语课。_________________________________
4). 昨天八点钟我们上了一节英语课。_________________________________
5).当ufo到达的时候你正在干什么？__________________________________
（二） 预习诊断. 词的适当形式填空：
1.i was in the____(barber) chair. 2. he ____( sleep) late when it arrived.
3. the alien visited the museum of _____(fly).
4. what was the girl doing when the ufo_____ (take) off?
（三） 预习反思 do you have any questions ?
二.课中实施
step 1 预习交流 step2 warming-up step 3 lead-in step4 pairwork
step 4 精讲点拨 : 1. 过去进行时：表示在过去某一时间内正在进行的动作。
构成：was / were + 现在分词
用法：1）过去进行时表现过去某一时刻正在进行的动作。
eg. she was writing a letter when i came in .我进来时，她正在写封信。
2）过去进行时还表示过去某阶段正在进行的动作。
eg. they were waiting for you yesterday . 他们昨天一直在等你。
2. when/while区别 :
_________we were watching the movie ,you closed the door。
we were watching the movie , ___________you closed the door 。
when既可指时间点，也可指时间段。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。while指一段时间，其引导的时间状语从句，主句用一般过去时，从句用过去进行时，或主从句都可用过去进行时。
step 5 拓展延伸：用when，while填空
1. __________ the alien was in the museum , i called the police .
2. the boy was walking down the street __________ a ufo landed .
3. _____ the alien was visiting the museum , the boy called the tv station .
