30 I am not a teacher .
Are you a teacher
Yes,I am.
No,I am not.
31 He isn't a nurse .
Is he a nurse
Yes,he is .
No,he isn't.
32 We aren't friends .
Are you friends
Yes,we are.
No,we aren't
33 Li Ming isn't a student.
Is Li Ming a student
Yes,he is.
No,he isn't.
34 Tom and Jim aren't at home.
Are Tom and Jim at home
Yes,they are .
No,they aren't.