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。

Oh. Not very far.

呵，不是很远。

I believe we should buy the smaller one.

我认为我们应该买较小的机子。

What do you find hardest in English?

你觉得学习英语哪方面最难？

OK. Thank you. Goodbye.

好的，谢谢您。再见！

People had to use other ways to record information.

人们只得使用其他方法记录资料。