她上课时眯眼看黑板。

She squints at the board during class.

上课时仔细听老师讲课。

Listen to the teacher carefully during the lesson.

上课时，我喜欢做笔记。

In class, I like to take notes.

你不应该在上课时打瞌睡。

You shouldn't doze off during class.

她喜欢在上课时坐在前排。

She likes to sit in the front row at school.

他喜欢在上课时嚼口香糖。

He likes to chew chewing gum during class.

在上课时，他总是很认真。

He is always very attentive at school.

我们的老师正在上课时很严格。

Our teacher is very strict when we are in class.

当你正在上课时，请不要玩手机。

Please do not play with your phone while you are in class.

上课时，老师要求学生们请安静。

During the class, the teacher asked the students to be quiet.