实战口语情景对话 第992期:Computers in Class 课堂上的电脑应用

重点讲解：
1. look up （在参考书、列表等中）查检（事实或信息）；
例句：You can look up this word in the vocabulary.
你可以在词汇表里查这个词。
2. put away 把…收起；放好；
例句：The table cloth was neatly folded up and put away.
桌布已整齐地折好放好。
3. be supposed to do sth. 应当，应该，须；
例句：You are supposed to be here at eight every day.
你应当每天八点到这里。
4. give back 归还；交还；
例句：My friend gave back the tools that he borrowed.
我朋友归还了他借的工具。