When a pencil is partly in a glass of water,it looks as if it _____.
问题描述：
When a pencil is partly in a glass of water,it looks as if it _____.
A.breaks B.has broken C.were broken D.had been broken
答案写的是C,
C为何用were而不是was呢?
答
as if 引导的句子用虚拟语气
又如：When he speaks ,as if he knew evrything.