听力原文：W: Well, how are you doing？
M: Fine. The computer section is coming along nicely. I should be finished with it by this afternoon.
W: Oh, that is great. But, I need to pull you off the computers for a little while and put you on something else.
M: Something else？
W: Yeah, yeah. Listen, you know about electricity, don't you？
M: Well, as that is the power source for most computers, I do possess a rudimentary knowledge of it of course.
W: Oh, that's great! That's just what I wanted to hear.
M: Uh, why？
W: Because of this.
M: The main circuit box？
W: That's right. Notice something odd about it？
M: Well yes. None of the wires appear to be attached.
W: Nobody gets to the heart of a problem as quick as you. Up to now, we've been powering the place with a generator, but it's time for that to stop. I want you to fix the circuit box.
M: Fix it？
W: Yeah, you know, attach the wires.
M: Un, am I to understand that you wish me to wire your building？
W: No, no. I don't wish you to do it. I want you to do it. You got everything you need here: transformer, wire, and fuses.
M: While I do know something about electrical current, I am not a certified electrician.
W: Did I say you had to be？
M: You don't understand. This job requires the services of a true professional.
(20)

A. He is a professional electrician.
B. He possesses a basic knowledge of electricity.
C. He knows nothing about electricity.
D. Electricity is his major.