PART C Directions: You will hear three dialogues or monologues. Before listening to each one, you will have 5 seconds to read each of the questions which accompany it. While listening, answer each question by choosing A, B, C or D. After listening, you will have 10 seconds to check your answer to each question. You will hear each piece ONLY ONCE. 听力原文：W: What' s the advantage of using nuclear power in the generation of electricity? M: In an advanced reactor, as much electricity can be made from one ton of enriched uranium fuel as from 75, 000 tons of coal. W: Then you need only a few lorry loads of fuel at a nuclear power station instead of many trains of coal. M: Exactly! W: With coal you have a residue of ash. What about the used fuel from a nuclear-powered station? W: Well, being radioactive, it can't be left lying around. M: So how do you dispose of it? M: It's loaded into thick steel flasks each weighing 45 tons. They' re dispatched to the United Kingdom Atomic Energy Authority for reprocessing. W: So there's little actual wastage? M: But that doesn't eliminate cost. The reprocessing isn't done for nothing. W: But electricity from a nuclear-powered station is cheaper than from a coal-fired plant, isn't it? M: Well, the cost of operation of nuclear stations is only half the cost of even the least expensive coal-fired stations. And later on the figures will show an even greater advantage for nuclear energy. W: But don't nuclear stations cost more to build? M: Yes, they do. However, their cheaper running gains more than offsets the construction costs. W: And aren't the nuclear stations cleaner in operation? M: Yes, and they' re better looking than conventional stations and can be built in places unsuitable for conventional plants. In most cases, they are safe. What are the two speakers talking about?