It's just had a baby,___.

问题描述:

It's just had a baby,___.
A.has not it
B.isn't it
C.has it
D.hasn't it
为什么不是B

D,'s这里面是has的简称,因为后面还有一个had,如果是is的话,那么就是被动语态了,而句子的意思是:它刚生了一个宝宝.