If we want to get some information about a new country, we could __________.

A．The need to exercise the memory.
B．How the brain differs from other body tissues.
C．The unconscious learning of a physical activity.
D．How nerves control body movement.

A．Why species don’t avoid extinction by adapting.
B．Why species become extinct at the rate they do.
C．Why humans aren’t extinct.
D．How many species aren’t extinct.