1、Unit 9 When was it invented Period 1 Section A 1a2clight bulbEdison is a great inventor.He had many inventions.Edison in。

2、Unit 9 when was it invented The first period 提示:提示: 1. take some things in the classroom. 2. ask students what are these。

3、Unit 9When was it invented Section A1bListen and match the inventions with the dates.abedc18761885192719711976dabec1c1c1。