No sooner had the bell rung____

问题描述:

No sooner had the bell rung____
A.when the class began B.than the class began C.while the class began D.then the class began 为什么选B呢?

no sooner ...than...= hardly...when...是固定搭配,表示一.就,样了.
这句话的意思是:铃声刚响课就开始了.