3.John isn't a diligent student,for it is the third time he has been late,______?a.wasn'tb.hasn't itc.isn't itd.hadn't he为什么选c，这个好像是反身什么，我忘了，具体讲一下，谢谢！
參考答案:是反意疑问句,前面是否定用肯定,是肯定用否定.但比如:I don't
thinkhe is smart,is he?而第三人称就不一样了，如：She thinks he isn't smart,doesn't?这是看人称的变化与哪个是主句．