whiCh oF thE Following is truE oF thE hEAting systEm oF thE johnstown CAmpus
A．thE hEAt is suppliED By humAn BoDiEs only.
B．thE hEAt is suppliED By Both humAn BoDiEs AnD othEr hEAtEmitting oBjECts.
C．thE hEAt is suppliED By Both humAn BoDiEs AnD ConvEntionAl FuEl.
D．thE hEAt is suppliED By humAn BoDiEs, othEr hEAtEmitting oBjECts, AnD ConvEntionAl FuEl.