1 sentence

1. 离开教室之前，请记得把所有的灯都灭掉。

   lí​kāi jiào​shì zhī​qián, qǐng jì​de bǎ suǒ​yǒu de dēng dōu miè diào.

   Please remember to turn off all the lights before leaving the classroom.

   Source: Dong Chinese Dictionary