听力题 Every human being, no matter what he is doing, gives off body heat. The usual problem is how to dispose of it. But the designers of the Johnstown campus of the University of Pittsburgh set themselves the opposite problem — how to collect body heat. They have designed a collection system which uses not only body heat, but the heat gives off by such objects as light bulbs and refrigerators as well. The system works so well that no conventional fuel is needed to make the campus''s six buildings comfortable. Some parts of most modern buildings — theaters and offices as well as classrooms — are more than sufficiently heated by people and lights and sometimes must be air-conditioned even in winter. The technique of saving heat and redistributing it is called "heat recovery." A few modem buildings recover heat, but the University''s system is the first to recover heat from some buildings and reuse it in others. Along the way, Pitt has learned a great deal about some of its heat producers. The harder a student studies, the more heat his body gives off. Male students give off more heat than female students, and the larger a student, the more heat he produces. It is tempting to conclude that the hottest prospect for the Johnstown campus would be a hard-working, overweight male genius.