The ideal title for this passage is______.

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

A．AIDS is a sign of moral failure and social collapse.
B．AIDS indicates that our social systems have been very inefficient.
C．The responses of a society to the threat of AIDS determines whether and to what extent the society can be called civilized.
D．The spreading of the fatal disease suggests that the nation' s resources have been wrongly use