Beyond a threshold world population of about ________, the quality of life declines.
a) 500 million
b) 1 billion
c) 2 billion
d) 3 billion
e) 6 billion
Answer: E
Beyond a threshold world population of about ________, the quality of life declines.
a) 500 million
b) 1 billion
c) 2 billion
d) 3 billion
e) 6 billion
Answer: E