老师进来时全班起立。

The class got up when the teacher came in.

《牛津词典》

正当同学们热烈讨论的时候，老师进来了。

The students were in the midst of a lively discussion when the teacher came in.

《新英汉大辞典》

我看小说太入神了，老师进来我都没注意到。

I was so absorbed in the novel that I didn't even notice our teacher come in.

youdao