:Unit 4 Learning about Language课件(人教版)选修8
:Unit 4 Learning about Language课件(人教版)选修8第5页

 (1)表时间, 相当于一个时间状语从句, 有时过去分词前可加连词when或while来强调时间概念。 ﹡Seen from the hill, the city looks like a beautiful garden. 从山上看, 这个城市就像一个美丽的花园。 ﹡When (you are) given a medical examination, you should keep calm. 当你做体检时要保持镇定。