现在完成时和现在完成进行时的比较 现在完成时和现在完成进行时的比较

3) 有少数动词用两种时态都可以，意思差别不大，如：
They have been working very well this term. 这学期他们学习很好。
They have worked very well this term.

It has been raining for two hours. 下了两个小时的雨。
It has rained for two hours.

I have been hearing from her regularly. 我定期收到她的来信。
I have heard from her regularly.

We have looked for mushrooms but have not found any. 我们找寻蘑菇但一无所获。