answer: #Person1# explains some points about the experiment that need attention before it starts. #Person2# reports to #Person1# that the air compressor doesn't work, so #Person1#'ll get #Person2# another one.
documents: #Person1#: Good afternoon, everyone. The experiment is to start at 3. Have you gone through the instructions? 
  #Person2#: Yes, sir. 
  #Person1#: 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. 
  #Person2#: Excuse me, sir. This air compressor doesn't work. 
  #Person1#: Have you turned it on? 
  #Person2#: Yes, I have. 
  #Person1#: Ok, I will get you another one. 
  #Person2#: Thank you.