M: Good afternoon, everyone. The experiment is to start at 3:00. Have you gone through the instructions?
M：同学们下午好，实验3点开始，你们都看过实验说明了吧？
W: Yes, sir.
W：是的，老师。
M: Ok, now some points for attention. First of all, pay attention to safety... Now, sign your names on the lab record, and after that you can start. If there is any question, just let me know.
M：好的，现在有几点需要注意。首先，要注意安全…现在，把你们的名字写在实验报告上，然后就可以开始了，如果有什么问题就告诉我。
W: Excuse me, sir. This air compressor doesn't work.
W：老师，这台空气压缩器不转了。
M: Have you turned it on?
M：你打开了吗？
W: Yes, I have.
W：打开了。
M: Ok, I will get you another one.
M：好的，我给你换一台。
W: Thank you.
W：谢谢。
