老师发现很难维持班级的秩序。

The teacher found it hard to keep her class in ___order.

当示威活动开始变得暴力时，警察被召来恢复秩序。

As the demonstration began to turn violent, the police were called in to restore ___order.

在混乱中，一些试图恢复秩序的警察甚至受伤了。

In the chaos, some policemen trying to restore ___order were even wounded.