He m_ his bus,so he had to wait for the next one.

He （missed） his bus,so he had to wait for the next one.
The meeting ended ten minutes ago.
=The meeting (has been over for) ten minutes/(since ten) minutes ago.
=(It's) ten minutes (since) the meeting ended. （此空可能有问题）

I heard from him days ago.
=I (have had) his letter (for) two days.
=(it's/has been) two days (since) I (received) his letter.

这是现在完成时改写句子的重要形式!
——满意请采纳,谢谢!——

He （missed)his bus,so he had to wait for the next one.
The meeting (has ended for) ten minutes.
I (had recieved)his letter (for)two days.
=(Before)two days (had) I(recieved) his letter