变一般疑问句 .否定句.否定回答.肯定回答 I‘m a doctor. 依次为:Are you a doctor?I'm not a doctor.Yes,I am.No,I'm not. You are a student. 依次为:Are you a student?You are not a student.Yes,I am.No,I'm not. It is my ruler. Is it your ruler?It isn't my ruler.Yes,it is.No,it isn't.