做作业是持续性动作,回家是非持续性的.
不同的动作做谓语和状语从句的时候,要用不同的介词.
习惯用法,记住就好了.
I was doing my homework when my father came back from work.
My father came back from work while I was doing my homework.
做作业是持续性动作,回家是非持续性的.
不同的动作做谓语和状语从句的时候,要用不同的介词.
习惯用法,记住就好了.
I was doing my homework when my father came back from work.
My father came back from work while I was doing my homework.