He turned back to help his friend.
She hurt her back while lifting heavy boxes.
Please call me back later.
How is your back pain now?
Could I get a back row seat?
I have some pain in my back.
When will you be coming back?
It is too tight across the back.
I'll come back on the 10th of July.
If he emails me, I will call him back.
Wherever you go, please come back by 10 pm.
OK, please place your backpack on the scale.