时间状语从句用法[急!!!在线等!]答:时间状语从句 从属连词有when, while, as, after,before, as soon as, the moment/minute/instant, since, hardly/scarcely/barely…when, no sooner…than…, till, until, once, whenever, directly(非正式用法)等等。when (当…时)―― In our city, school buses are used only when(当…...