题目内容：
The main idea of the third paragraph is that__________.
A．the mass of the fish decides the intensity of electric power it generates B．the strength of shock given by a young electric ray can only light the bulb of a pocket flashlight
C．to make full use of the energy produced by electric fish, suitable wires should be available
D．a mature torpedo is capable of producing enough electricity to knock down a man
参考答案：
答案解析：