Tom and Jerry are both students of Mr. Lee. They all know that Mr. Lee’s birthday is one of the ten next.

4^th March	5^th March	8^th March	4^th June	7^th June
1^st September	5^th September	1^st December	2^nd December	8^th December

Mr. Lee told Tom the month and told Jerry the day. Then he wants them to guess his birthday.

Tom said: If I don’t know. Jerry can’t know at all.

Jerry said: At first, I don’t know, but now I know.

Tom said: So I know it too.

Do you know when Mr. Lee’s birthday is?