6、过去进行时
We were talking about you a moment ago. I was playing the piano when she came in.
7、将来进行时
What will you be doing this time tomorrow? I believe he‘ll be coming soon.
8、现在完成时
8.1、过去发生但对现在有影响的动作，常跟时间状语already， yet， never， before， recently， just， ever， once连用。
I have been to Peking many times. They have already published the results of their experiments.
8.2、从过去某时间开始一直延续到现在(可能还要继续下去)的动作，常跟时间状语since， for two years，
so far， in recent years等(使用延续性动词)
He has lived here since 1984. I have studied English for two years.
1)他参军已经有十年了。 ①He has been an armyman for ten years.
②It is(has been)ten years since he joined the army.
③He joined the army ten years ago.
