The ideal title for this passage is ________.

A．a mature torpedo is capable of producing enough electricity to knock down a man
B．the mass of the fish decides the intensity of electric power it generates
C．the strength of shock given by a young electric ray can only light the bulb of a pocket flashlight
D．to make full use of the energy produced by electric fish, suitable wires should be available

A．the current in one place is not strong enough to give a shock
B．the fish' s electric ceils are filled with jelly-like substance
C．to complete the circuit, you have to touch the fish in two places
D．a torpedo' s electric cells contain more than one electric plates