他上课真很有趣，当他认为我们疲倦的时候，就给我们讲笑话。

He's really amusing and tells jokes when he thinks we're getting bored.

youdao

他上课真很有趣，当他认为我们疲倦的时候，就给我们讲笑话。

He's really amusing and tells jokes when he thinks we're getting bored.

youdao