精选优质文档-倾情为你奉上人教版九年级英语Units9-10单元知识结构单元功能语言重点短语重点语法UNIT 9When was it invented?谈论发明1. When was invented? It was invented .2.Who were they invented by?They were invented by .3. What are they used for?Theyre used for .4.What do you think is the most helpful invention?I think the most helpful invention is be invented by sb.be used for doing sth. =be used to do sth.shoes with adjustable heels see in the darkchange the style of the shoeslight b
