Unit 6 When was it invented?
The Second Period Section A 2d / SectionB 1a–1e
Teaching aims（教学目标）
一、通过学习，掌握下列词汇：sou r, customer，website, list, mention, pione er了解以下词汇：crispy, by mistake，electricity, zipper
二、口、笔头掌握以下句型：
1. The zipper was invented by Whitcomb Judson in 1893.
2. Potato chips were invented by mistake.
3. The customer was happy in the end.
4. They were invented in 1863.
5. George wanted to make the customer happy.
三、能用过去的被动语态（肯定、否定、及疑问句形式）熟练的谈论某些发明。
