How many tablets at most can a person over 12 have in 24 hours

A．helps you to fall asleep quickly
B．may be dangerous to small children
C．cannot be taken if one feels sleepy
D．should not be taken by children under six

A．the second largest continent in the world
B．a dangerous and unpleasant insect
C．farmland in the heart of Africa
D．a kind of illness that can destroy cattle