麻烦帮我改一下这个倒装句的自然语序

对的~~
就是The bell had no sooner rung than the teacher came in
no sooner。。。 than。。。 "一。。。就。。。"
引导时间状语从句,主句用过去完成时,"than"后面的从句用一般过去时。(从这里可以知道,no sooner后面是主句;than后面是从句)
例:
I had no sooner reached home than it began to rain。
我一到家天就下起雨来
No sooner 。。。than。。。常放在句首,表示强调。这时主句要倒装。
例:No sooner had I reached home than it began to rain。