The riots took place against a background of widespread unemployment.是什么意思？

The riots took place against a background of widespread unemployment.

暴乱是在普遍失业的情况下发生的。

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

riots

n. 暴乱( riot的名词复数 )，骚乱，极度丰富，非常有趣的人（或事）；v. 暴动，闹事( riot的第三人称单数 )；

例句
More than 240 England football fans are being deported from Italy following riots last night.
昨晚的骚乱发生后有240多名英格兰球迷被驱逐出意大利。

took

v. 拿( take的过去式 )，接受，学习，取得；

例句
The interview took place on a Friday afternoon...
采访是在一个星期五的下午进行的。

place

n. 位，地方，职位，座位；vt. 放置，获名次，投资，评价；vi. 得名次，名列前茅，[美国英语][赛马]得第二名，准确把…推到预定地点；

例句
The interview took place on a Friday afternoon...
采访是在一个星期五的下午进行的。

against

prep. 反对，对…不利，紧靠，以防；

例句
His hand brushed against hers; it could have been either accidental or deliberate.
就在有意无意间，他的手轻轻拂过她的手。

background

n. （画等的）背景，底色，背景资料，配乐；

例句
The Pope has sent a message appealing for unity in his homeland, against a background of divisions in the Solidarity movement...
团结运动中各派搞分裂，在此情况下教皇发出号召，呼吁祖国保持团结。

of

prep. 关于，属于…的，由…制成；aux. 助动词 [非标准用语、方言] =have [主用于虚拟语气]；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

widespread

adj. 分布广的，普遍的，广泛应用，普及的；

例句
The deaths occurred when police acted to stop widespread looting and vandalism...
警方采取行动制止猖狂的打砸抢行为时有多人丧生。

unemployment

n. 失业，失业率，失业状况，失业人数；

例句
He will appeal to the state for an extension of unemployment benefits...
他将呼吁国家延长领取失业救济金的时限。