What' s the population of the USA according to the text（）

A．make up nearly halt' of the American population
B．are deeply interested in making a better life for all people
C．have not been given a fair chance before now
D．are always finding fault with their parents

A．People haven' t written much about American youth.
B．Writers have wasted a great deal of their effort to write about American youth.
C．Much has been written about American youth.
D．Young people' s ideas are not important enough to the USA.