We all know( ).括号填1when does the class begin 2when does the class begins 3when the class begin选

题目

We all know( ).括号填1when does the class begin 2when does the class begins 3when the class begin选

答案

不是疑问句不需要倒装,class是单三；
应该这样说才对：
We all know when the class begins.