约4520字。

　　Unit 9  When was it invented?教学案
　　1． invent  vt发明，创造       n. inventor发明家  invention发明
　　Edison is a famous inventor, he invented the electric lamp, and it is a great invention.
　　区别invent, discover, find, find out，create
　　※invent指发明原来不存在的东西      e.g. Who invented the computer?
　　※discover指突然或偶然发现原来就存在但一直未被认识的事物   discovery  n.
　　Eg. Who discovered America?
　　※find指寻找的结果，即“找到” e.g.I’m looking for my pen ,but I can’t find it.
　　※find out指经过观察，调查把某事，某物查出来，搞清楚，弄明白
　　Eg Please find out when the train leaves.
　　※create 创造(精神领域的东西，如文学作品等）  creation n.    creative adj.
　　Eg. He is famous for the novel he created last year.
　　2. be used for doing sth./ to do sth. 被用来（做）…… Clothes are used for keeping warm.
　　e.g  Thermos is used for keeping hot water.   The refrigerator is used for keeping food.
　　used to do sth. ________________ be/get used to dong sth._________________________
　　3. operate v. 运转，操作  n. operation 操作，运作，手术  vi. operate on sb.给某人做手术    
　　e.g.  1)Do you know how to operate the heating system?
　　2)The doctor is operating on him.          3) The machine is operating well.
　　4. heat   v. (up) （把……）加热，（使）变热  e.g We will heat (up) some milk for the coffee.
　　a heated swimming pool温水游泳池
　　heat   n.  1.(U) 热的程度，温度；热，高温；激烈，热烈（状态，时刻）
　　e.g. 1) The heat from the fire dried their clothes.   2) I can’t walt in this heat.
　　3)In the heat of the argument, I lost my self-control.
　　2. (C)分组赛，预赛   e.g. She was knoct in the qualifying heats.
　　5.  according to   1.根据……所说，用来表示信息来自别人或别的地方，而不是来自我们自己已知的情况，不与opinion或view类的词连用（in one’s opinion/ view）
　　e.g. 1) According to our records, the boo have borrowed should now be returned to the library.        2) According to George, she is really a good teacher.
　　2.随着…而作（相应的）变更 e.g.We will be paid according to the amount of work we do.
　　6. remain vi. (一般不用进行时)停留，留下  + to do/n./adj./adv./prep.短语等，“继续保持，依然不变”（时过境迁之后，仍然保持原有的状态或身份）
　　e.g.1）She remained at home to look after the children. 
　　2）Little of the original architecture(建筑)remains.
　　3）The only remaining question is whether or not we can raise the