The prisoners rioted against mistreatment by sadistic guards.是什么意思？

The prisoners rioted against mistreatment by sadistic guards.

囚犯因不堪忍受狱警施虐而发动了暴乱。

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。

prisoners

n. 囚徒( prisoner的名词复数 )，俘虏，被夺去自由的人[动物]等；

例句
The regulations were relaxed and the prisoners could get out and about a bit.
规定有所放宽，犯人可以出去短暂放风。

rioted

v. 暴动，闹事( riot的过去式和过去分词 )；

例句
They rioted in protest against the government.
他们发动暴乱，以抗议政府的行为。

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。

mistreatment

n. 虐待；

例句
Monroe was on the phone, raging about her mistreatment by the brothers...
门罗正在打电话，怒不可遏地说着她被这几个兄弟虐待的事。

by

prep. 在…旁边，表示方式，由于，经过；adv. 经过，表示保留或保存时用，短暂拜访；

例句
...expensive make-up that we saw being advertised by a beautiful model...
我们所见的由一位漂亮模特代言的昂贵化妆品

sadistic

adj. 虐待狂的；

例句
The prisoners rioted against mistreatment by sadistic guards.
囚犯因不堪忍受狱警施虐而发动了暴乱。

guards

n. 卫兵( guard的名词复数 )，警戒，警卫队，防护装置；v. 保护，控制( guard的第三人称单数 )；

例句
...the bright uniforms of the guards parading at Buckingham Palace.
参加白金汉宫阅兵式的卫兵们色彩鲜艳的制服