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 capacity to generate electricity is the distinctive characteristic of the fish
B．the current travels in an upward direction from the positive side to negative side in torpedo's electric cells
C．some fish can produce enough electricity to drive a number of electric motors
D．the torpedo' s electric cells have a shape with six sides