读音一样door怎么读，都读/r/音。

They run a small grocery store.

他们经营一家小食品杂货店。

When I give the signal , run!

我一发信号，你就跑！

She took the stairs at a run.

她跑着上了楼梯。

I go for a run every morning.

我每天早晨都去跑步。

You can't run on a full stomach.

饱餐之后不能跑步。

I heard a knock at the back door.

我听到后门传来敲门声。

run中的r发【r】，door中的r不发音或者认为与oor一起发长元音[ɔ:(r)]，最后的r可发音也可不发音