You owe a certain person a sum of money.

你欠着某人一笔钱。

《柯林斯英汉双解大词典》

To date, the sum of my gardening experience had been futile efforts to rid the flower beds of grass.

迄今为止，我全部的园艺经验就是给花圃徒劳地除草。

《柯林斯英汉双解大词典》

Let x be the sum of a and b.

设x为a加b之和。

《牛津词典》

Every president is the sum of his past experiences.

VOA: standard.2010.01.16

So, the total work that we can get out must be zero, out of the whole sum of them.

因此，我们可以从这两个热机,得到的总功，一定是零。

麻省理工公开课 - 热力学与动力学课程节选

It's just minus the sum of all these things, because of course these are just defined as the work done by the environment to the system.

等于负的这些东西的和，因为它们的定义是,环境对系统所做的功。

麻省理工公开课 - 热力学与动力学课程节选

The sum of it was a too distant cousin of the German biergarten ideal I sought.

BBC: The wiedergeburt (rebirth) of New York��s biergartens

In simple terms, economic value-added is almost entirely defined by the sum of wages and profits.

FORBES: Investment and Technological Progress

But even that vast sum of taxpayer lucre cannot will the necessary innovations into being.

FORBES: Government Mandates Make Health Savings More Elusive