Before you leave the lab, make sure the electricity is turned off and the windows are shut.

你们离开实验室前，务必要关上电源，关好窗户。

Have a nice time in Guangzhou. And say Hi to Bob from me.

祝你在广州玩得愉快。并请代我向鲍勃问好。

Shooting. Do you like shooting?

射击。你喜欢射击吗？

What can you suggest?

你有什么建议吗？

That sounds a great idea. Good luck with your trip!

听起来真是个好主意。祝你一路顺风。

What happened before printing was invented?

印刷术发明以前是怎么一回事？