Weegy: D. both a and b. Matter is needed to transfer thermal energy by conduction and convection. User: One consequence of the third law of thermodynamics is that
A. heat engines have efficiencies less than 100 percent.
B. in some energy conversions, energy is not conserved.
C. engines cannot discharge waste heat.
D. the work a heat engine produces is less than the waste heat it produces. Weegy: One consequence of the third law of ... (More)