你们预习这一课了吗?。

Have you prepared this lesson?

你们要分组展示预习成果。

You shall work in pairs or groups to show the preview results.

你在上课前有预习的吗？

Did you preview before the class?

昨晚多几分钟的预习准备，今天上课少几十分钟的烦恼。

Last night more than a few minutes of preparation, few minutes less trouble in class today.