单句改错。下面各句中有错误，请指出并改正。( 注意：只有一处错误 )
1. When to hold a meeting to settle the problem haven't been decided.
2. He promosied me that he will never lie to me again.
3. Tom never gave in any difficulties.
4. He worked here since graduation.
5. I am very sad because I have no partner to speak English.
6. They made up their mind to work hard.
7. It is a great fun to go camping with friends.
8. I agree with what you said but I don't agree with anything.
9. The policeman couldn't see which direction the car went.
10. After he failed once, he tried the second time.
