He’s quiet as a mouse in class.

上的时候他总是悄没声儿的。

I have to go now because I must be punctual for class.

我现在不得不走了, 因为我得准时上。

He often reviews today's lessons for tomorrow.

他常为明天上而复习今天的功。

I'm constantly having to mug up things ahead of teaching them.

我经常不得不在上前攻读要讲的东西。

The teacher took attendance at the beginning of every class.

每次一上都要点名。

The late boy made a beeline for his classroom.

迟的男孩抄捷上。

The children were taught individually, not in a group.

孩子们被个别教授，而不是一起上。

I will inquire when to begin our lessons.

我要问一下我们什么时候开始上。

Tom did play hookey, and he had a very good time.

汤姆真的没上，而且痛痛快快地玩了一场。

I made the zip gun in class out of a toy airplane launcher.

我在上时用玩具飞机发射器改制成了这把枪。

I was late for a class.

我上迟了。

He fell asleep during the lesson.

他在上时睡着了。

Topsy had an uncommon verbal memory, and committed with a fluency that greatly encouraged her instructress.

托普西对文字的记忆力非常强，上时对答如流，使她的教感十分鼓舞。

The bell sounded for the beginning of the lesson, and, right on cue, the teacher walked in.

上铃响了，就在这时候走了进来。

It's time for class.

上时间了。