A、Because he did not take with him the necessary parts. B、Because he did not know what he needed for the repair. C、Because it to

W: Good morning. My name’s William Johnson from an electronics company in Boston. I’d like to speak to Paula Brown, please.
P: Good morning, Mr. Johnson. How are things in your company?
W: Not as good as I had hoped, Mrs. Brown.
P: Oh, I’m sorry to hear that. What’s wrong?
W: You sent an engineer, a Mr. Bains, to repair the faulty valves on the pipe system you installed last year and he came without the necessary equipment. He tells me it will take him a week to get what he needs. We told him what he needed and yet he came here with nothing.
P: I guess he had to make an inspection to see what he had to get to do the repair.
W: Mrs. Brown, you know that is not true. We told you what was needed and now we have a further delay. It seems to me he has wasted his time coming to Boston. And in the meantime, we cannot use the pipes.
P: Well, where is Mr. Bains now, is he still with you?
W: I think he has gone now to his hotel. He told me he would return with the parts he needs but he didn’t say when exactly.
P: Leave it to me, Mr. Johnson. I’ll call him and talk to him myself. I’m sure we’ll work something out in a day or two.
W: I hope so, Mrs. Brown, because you know we are not very happy with the service you have provided for us. At the beginning it was fine, there were no problems, but now we have a little technical fault and we have wasted a lot of time.
P: I understand. Don’t worry. We’ll work it out.
W: Yes. It’s very important, Mrs. Brown. We don’t have much time.
P: Okay, I’ll talk to Mr. Bains and call you later today or tomorrow morning.
W: Right. I hope you have good news for me. Goodbye.
P: Goodbye, Mr. Johnson.
Question No. 19 What did the man complain about?
Question No. 20 How soon did the woman promise the man that the problem would be dealt with?
Question No. 21 Why was the engineer Mr. Bains unable to do the repair?
Question No. 22 What would the woman do after her talk with the man?