A、Doctor and patient. B、Doctor and nurse. C、Friends. D、Colleagues. D从workplace，X-ray等词提示，本对话发生在医院。又从poor management，health hazar

W: I don’t know what to do. I can’t see, to get anyone in the hospital to listen to my complaints, and this outdated equipment is dangerous. Just look at it.
M: Hmm, uh, are you trying to say that it presents a health hazard?
W: Yes, I am. The head technician in the lab tried to persuade the hospital administration to replace it, but they are trying to cut costs.
M: You are pregnant, aren’t you?
W: Yes, I am. I made an effort to get my supervisor to transfer me to another department, but he urged me not to complain too loudly, because the administration is more likely to replace me than the X-ray equipment. I’m afraid to refuse to work, but I’m more afraid to expose my unborn child to the radiation.
M: I see what you mean. Well, as your union representative, I have to warn you that it would take quite a while to force management to replace the old machines, and attempt to get you transferred may or may not be successful.
W: Oh, what am I supposed to do then?
M: Workers have the legal rights to refuse certain unsafe work assignments under two federal laws: the Occupational Safety and Health Act and the National Labor Relations Act. But the requirements of either of the acts may be difficult to meet.
W: Do you think I have a good case?
M: If you do lose your job, the union will fight to get it back for you along with back pay — your lost income. But you have to be prepared for a long wait, maybe up to two years.
Questions 16-20 are based on the conversation you have just heard:
16. What does the woman complain about?
17. What’s the possible relationship between the man and the woman?
18. What has the woman asked her supervisor to do?
19. What does the man say about the two federal laws?
20. What will the union do if the woman loses her job?