altered muscles and like all muscles are apt(likely) to tire, so they are not able to produce electricity for very long.
The power of producing electricity may serve these fish both for defence and attack.

The reason why the electric eel is able to give more powerful shock is that （）.

A．the working system of the electric plates in the eel is the most effective
B．the working system of the electric plates in the eel is far inferior to those in the torpedo
C．compared with those in the torpedo, the working system of, electric plates in the eel is more direct and efficient
D．compared with other electric fish, the eel possesses much more electric plates