Every human being, no matter what he is doing, gives off body heat. The designers of the Johnstown campus of the University of Pittsburgh set their hearts on how to collect body heat and utilize it. They have designed a collection system which utilizes not only body heat, (1)____________________________________.
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, theatres and offices as well as classrooms are heated by people and lights. (2)_____________________________. A few modern buildings 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. (3)__________________________ , and the larger a student, the more heat he produces.
