老师发现很难维持课堂秩序。

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

当示威开始变得暴力时，警察被叫来恢复秩序。

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

经过一番激烈的讨论，主席宣布会议开始。

After some heated discussion, the chair called the meeting to ___order.