A．There might be an increase of 2.2 billion persons from 1975 to the year 2000.
B．About 50,000 babies are born annually at present.
C．Between 8000 B.C. and the present, the population increase is about 80,000,000 persons each year.
D．The population increased faster between 8000 B.C. and 1650 than between 1650 and the present.