时间状语从句讲解与练习 when, while 和 as 引导时间状语从句的用法这三个词的意思很简单，都有“当时候”的意思, 但又有区别。一、when 的用法观察下面的句子:1. When he was a child he was always trying out new ideas. 他小时候就常常试验一些新的设想。 2. When she came into my room, I was just reading a book. 她走进我房间时，我正在看书。3. Were you writing when the teacher came in? 老师进来的时候，你在写信吗？4. Sorry, I was out when you called me. 对不起，你打电话来的时候我出去了。5. He was leaving when someone knocked at the door. 他正要走，这时有人敲门。 6. I thought of it just when you opened your m
