单项选择题

Usually you will not get a shock by touching the electric ray in one place only because （）

A．the current in one place is not strong enough to give a shock
B．the fish's electric cells 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

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单项选择题

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

单项选择题

The main idea of the third paragraph is that （）

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