are those your sisters A yes,they are B no,they're not C no,they aren't 选哪个

问题描述:

are those your sisters
A yes,they are B no,they're not C no,they aren't 选哪个

A肯定没问题。

B 和 C 唯一的区别就是写法.
所以排除
因此选A.

选A
是,她们是

A. 是的,她们是

选A.
题目问题否定形式应为no,they are not

感觉A.C都对。但不能用they're not简写形式。