When we were having our supper,Tom came in

问题描述:

When we were having our supper,Tom came in
这句话是说:当我们吃晚饭的时候,Tom进来了
还是:我们正在吃晚饭时,Tom 进来了?
为什么要用 came 而不是 come

我们正在吃晚饭时,Tom 进来了.