they stood chatting together as easily and naturally as___ A it could be B.could be C.it was D.was这是零八年的专四一道选择题 为什么不能选A

问题描述:

they stood chatting together as easily and naturally as___ A it could be B.could be C.it was D.was
这是零八年的专四一道选择题 为什么不能选A

因为主语是they,A改成they could be就可以了.