a girl balances on one leg, holding her foot and glowering at a blushing boy, while another young couple dance in the background.

VOA: standard.2010.08.09

Let me give a little bit background on positive psychology: how we came about and how this class came about.

下面介绍一下积极心理学的背景：,它是如何诞生的，这门课是如何诞生的。

哈佛公开课 - 幸福课课程节选

So, let me begin by doing a little bit of background so you know what's going on here.

首先，我要做一下背景介绍,你们就能了解情况了。

麻省理工公开课 - 固态化学导论课程节选

And,each player's observations and interactions with the local people vary greatly, depending on his background.

VOA: standard.2009.11.05

So if you're coming from prior background, your code might work a little differently on a different system if you don't use those flags.

如果你来自一个先前的背景，如果你们没有使用这个版本标志的话，在一个不同的系统中,你的代码可能运行地不太一样。

哈佛公开课 - 计算机科学课程节选

"We think that you ought to have a background check at gun shows. We think you ought to have a background check so that people who are dangerously mentally ill aren't getting their hands on guns."

VOA: standard.2010.04.19

All right. With that by the way of background, let's go on to two -what we might call rhythmic devices here--two rhythmic devices.

以此为背景知识,我们来继续学习,两种节奏类型

耶鲁公开课 - 聆听音乐课程节选

"President Obama, based on an earlier story,had asked that the national security team gather further information on his background, including concerns that he might have been involved the deaths of a significant number of Taliban prisoners of war a few years ago.

VOA: standard.2009.08.17