back是一个英文单词，名词，翻译为“背部、脊梁骨、后部、背面、末尾、（椅子）靠背、后卫、船体、（飞机）机身、（人的）躯干”。

英 [bæk]   美 [bæk]

n.(人体或动物的)背部；背；腰背；脊柱；脊梁骨；后部；后面；末尾

adj.背后的；后面的；后部的；过去的；旧时的；到期未付的；拖欠的

adv.向后；在后；在背面；与(某物)有距离；控制住；忍住

v.(使)后退；倒退；帮助；支持；下赌注于(赛马、参赛队伍等)

Or the back of your knee?

或者你的膝盖背部？

Someone must be at the back of this.

这事一定有人在背后捣鬼。

How far back should I have to go? Tell me.

多远才是我该回去的距离？告诉我

There are a lot of people back there waiting to get in.

后面有许多人等着进来。

There's room for three people in the back.

后排有可容三人的空位。

I need time to get my wind back after that run.

我跑过之后需要时间喘口气。