Xià le kè jiù qù mǎi shū.
37. 快下楼去看看吧。
Kuài xià lóu qù kànkan ba.
Come downstairs and have a look.
38. 飞机上了我弟弟就睡觉。
Fēijī shàng le wǒ dìdi jiù shuìjiào.
My brother went to bed as soon as we got on the plane.
39. 我写完了作业就出去玩儿。
Wǒ xiě wán le zuòyè jiù chūqù wánr.
After I finished my homework, I went out to play.
40. 请快进教室来。
Qǐng kuài jìn jiàoshì lái.
Please come into the classroom quickly.