It's too tight across the back.

背部太紧。

《牛津词典》

He opened the back door.

他打开了后门。

《柯林斯英汉双解大词典》

I patted her on the back.

我拍了拍她的背。

《牛津词典》

So "The Back-Up Plan" is to become a single mother with the help of modern science.

VOA: standard.2010.04.30

We have a Sumerian story about the third millennium BCE, going back 3000--third millennium, 3000 BCE.

苏美尔人有一个关于公元前三千年，一直往回3000年，公元前。

耶鲁公开课 - 旧约导论课程节选

Having done that, it goes back up and picks the second sub-list, which came from there. It's a down to base case, merges it.

就是从那里得来的,完成这些后,回到上一步。

麻省理工公开课 - 计算机科学及编程导论课程节选

All the back-end hardware and maintenance is taken care of by tech consultant Affordable Business Solutions.

FORBES: Microsoft Knits Windows Into India

The back-and-forth between the three filmmakers continued, the viability of their collaboration still not fully confirmed.

NEWYORKER: Beyond the Matrix

The John Lennon Educational Tour Bus sets out for the back-to-school tour this week.

FORBES: John Lennon Tour Bus Goes Back To School