Everyday Expressions I don't know what to do next. How did you know him to be the headmaster? How should I know? I know of it, but I don't know it well. Do you know him? 生活用语 Street Talks I didn't know whether to send the letter airmail or not. I don't know if I can stay late. He is known to everybody. God knows where he has gone. I have to wear more. It's very cold, you know. (不是吗?插入语) Do you know where David is going to? How should I know? (我怎么晓得?) I don't know that I can get up by five o'clock. You know Beijing Hotel? Well,the bus stop is a few yards farther down the road. Do you know, I think I'll accept your invitation,in spite of what I said just now. 谚语 Proverbs We don't know when we are well off. 我们不知道何时富有。 All that we know is that we know nothing. 我们只知道我们什么都不知道。 No one knows what will happen to him the next moment. 没人知道呆会儿自己会出什么事。