Soldiers in ancient times often went to fight on the backs of African elephants.

古代的士兵经常骑在非洲象的背上作战。

youdao

Remember to scrub all surfaces, including the backs of your hands, wrists, between your fingers, and under your fingernails.

记得要擦洗到所有表面，包括手背、手腕、手指间和你的指甲下面。

youdao

The backs of his thighs tingled.

他的两条大腿后侧略感刺痛。

《柯林斯英汉双解大词典》

There were many other similar creatures. They had ridden behind me on the backs of large animals.

VOA: special.2010.07.17

But the president says he will not let health reform be paid for in his words -- "on the backs of middle-class families."

VOA: special.2009.07.25

Thousands more are reported trapped in a no-man's land between the violence at their backs and a frontier ahead of them.

VOA: standard.2010.06.15

These companies are interested in building their businesses upon the backs of their employees.

FORBES: An End to 401(k)s (February 1, 2002)

They also provide for claw-backs of bonuses which turn out to have been unfounded.

WSJ: Bankers Are Still There for Bashing

"Bulgaria's financial stability has been built on the backs of the ordinary people, " says Mr Hristov.

BBC: Bulgaria cabinet faces tough task of tackling poverty