when shall we go to the museum,this afternoon or tomorrow morning?_____is OK.I'm free these days.

问题描述:

when shall we go to the museum,this afternoon or tomorrow morning?_____is OK.I'm free these days.
A.both B.all C.either D.neither
选哪个?为什么?

C,both用于复数,后面是is,所以用either
neither表示否定,all 用于三者或三者以上.