A: Do you have new teachers, Tom?  

B: Yes.

A: Who are they?                 

B: Mr. Lin and Mr. Sun.

A: Are they young?       

B: Mr. Lin is young, but Mr. Sun isn't.

A: Is Mr. Lin a university student?  

B: Yes, he's very funny.

A: Is Mr. Sun strict?        

B: Yes, but we all like him.