How often is physical science more accurate than biological science（）

A．He happened to fly over it.
B．He remembered it himself.
C．He made a guess and happened to be right.
D．He figured it out with the help of some simple instruments.

A．on aviation history
B．about a man called Lindbergh and his plane
C．about a famous flight across the Atlantic
D．about how to go to Paris from New York by plane