24（）

单项选择题In the drawing and cartoons of Uncle Sam （）

A．he wore the stars and stripes
B．he never had a beard
C．he had no hair
D．he wore a bow tie

单项选择题The brain works much more efficiently when （）.

A．both sides of the brain are used equally
B．the left side is fully developed
C．scientists work on it
D．the fight side is fully developed