把下列英语句子改为否定句,一般疑问句,肯定回答句,否定回答句答:2.My brother is not a student, Is your brother a student?--Yes,he is /No,he isn't 3.Mike and Amma are not students. Are Mike and Amma students?--Yes,they are/No,they aren't.4.I am not a doctor. Are you a doctor?--Yes, I am/No, I am not.5.He i...