用下列单词填空完成下面对话.A:Is Peter your elder__1__?B:No.He's my __2__?

用下列单词填空完成下面对话.
A:Is Peter your elder__1__?
B:No.He's my __2__?
A:Is he a __3__?
B:Yes.Heis a __4__ student.
A:Which --5-- is he in?
B:Three.
A"How __6__ is he now?
B:Twenty-one.
A:What is he going to __7__ when he graduates from the college?
B:A computer __8__.
A:What subject does he __9__ in?
B:Computer __10__.And he __11__ very hard at it.
A:Good.I'm __12__ he will be a very good engineer.
B:Maybe he is.