ache

我下背部有点痛。

I've got an ___ache in my lower back.

因为一整天坐在书桌前，他的背开始疼了。

His back began to ___ache from sitting at the desk all day.

从那以后，我的左腿就一直痛。

Since then, I have had an ___ache in my left leg.