[填空题]
It has been suggested that a heat engine could be developn 7-b6vcqbgd5 ed that /a +v7auwyb h9made use of the temperature difference between water at the surface of thevwuh9ay 7/+ab 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?
