Question

while引导的时间状语从句是什么语态

Answer 1

while "当……时候"，有表示一段时间的含义在里面，引导时间状语从句，所以它后面的句子的谓语动词是连续性的或表状态的，其时态可以是一般时态（表状态）或进行时态（连续性动作）：

He saw a snake while he was in the mountains.他在山里的时候见到了一条蛇。

I was doing my homework while my brother was playing with his toys. 我弟弟在玩玩具的时候我在做家庭作业。