完形填空

A: What's wrong with you?

B: I have a 1.

A: Let me check.2your mouth and say "ah”.

B: Ah...

A: You have a 3tooth.

B: What 4 I do?

A: You should brush your 5 after eating.

B: All right.

A: You shouldn't cat too 6 sweets.

B: OK. Thank you.