[填空题]
It has been suggested that a heat engine d 3oob tirs*9.could be developed that made xb cziwevcj6(3/9 4cvuse of the temperature difference bwzc / x4cv3 vjbeic(69etween water at the surface of the ocean and that several hundred meters deep. In the tropics, the temperatures may be 27$^{\circ}\,C$ and 4$^{\circ}\,C$, respectively.
(a) What is the maximum efficiency such an engine could have? %
(b) Why might such an engine be feasible in spite of the low efficiency?
(c) Can you imagine any adverse environmental effects that might occur?
