8 interesting English sentences

Well, xielaojiu posted one of the sentences and link on his blog, and after a look, I found it fancy so I paste them here. Have you got the meanings of these sentences?

1. Never trouble trouble till trouble troubles you.
2. I think that that that that that student wrote on the blackboard was wrong.
3. I know. You know. I know that you know. I know that you know that I know.
4. We must hang together, or we'll be hanged separately.
5. The quick brown fox jumps over a lazy dog.
6. Was it a bar or a bat I saw?
7. To China for china, China with china, dinner on china.
8. 2B or not 2B, that is a ?

Here is the link as well, but it contains Chinese characters.