题目内容：

The students were talking loudly_the teacher came in.
A.when B.as soon as C.while D.until

优质解答

A ,四个选项里 只有when 可以和瞬间动词连用.
老师进来 是一个瞬间 所以不能选 C
D 选项是 直到.才的意思.
不能说同学们正在说话直到老师进来.