Good afternoon, everyone. The experiment is to start at 3. Have you gone through the instructions?
Yes, sir.
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.
Excuse me, sir. This air compressor doesn't work.
Have you turned it on?
Yes, I have.
Ok, I will get you another one.
Thank you.