【单选题】Choose the best answer. 选择最佳答案。 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 Universi...
A.
The heat is supplied by human bodies only.
B.
The heat is supplied by both human bodies and other heat-emitting objects.
C.
The heat is supplied by both human bodies and conventional fuel.
D.
The heat is supplied by human bodies, other heat-emitting objects, and conventional fuel.