Welcome to the unit

1. listen to a headmaster talking about...

2. know of ; know about; know from ( 区分= tell from)

eg: 1) 我不认识他，但是我知道他。 2）他们想了解美国英语和英国英语的区别。 3） 我们应该分清敌友。

I don’t know him but I know of him.

They want to know about the differences between American English and British English.

We should know a friend from an enemy.

talk of / talk about; hear of / hear about/ hear from