A．Help others for nothing in return.
B．Save money to help others.
C．Try to make more money.
D．Get help from the rich ones.
A．They care too much about people they love.
B．They are troubled by what others say.
C．They are more easily to be rated by others.
D．They tend to be the object of envy.
A．The right brain hemisphere remains awake all night long.
B．Both hemispheres of the brain remain active all night long.
C．The left brain hemisphere remains awake during deep sleep.
D．One brain hemisphere remains more awake than the other during deep sleep.