A．With the use of a computer．
B．With the help of the teacher．
C．All by themselves．
D．By inputting some information into their brains．
A．Helping them learn more knowledge．
B．Restraining them from engaging in criminal activity．
C．Tracing them when they escape．
D．Taking care of their children．
A．Enemies exist in everyone's life．
B．Humble people have fewer enemies．
C．It is terrible to have enemies．
D．Generous people are popular．