At the Beginning of the Twentieth Century,the World's Population Was

Multiple Choice

At the beginning of the twentieth century,the world's population was about _________.One hundred years later,there were roughly __________ people in the world.

A) .2 billion;1 billion
B) .5 billion;3 billion
C) 1 billion;4 billion
D) 1.6 billion;6 billion
E) 2 billion;10 billion