题目：On an average, people in America who were born in 1900 ______.A．had a life-span of 74 year
On an average, people in America who were born in 1900 ______.
A．had a life-span of 74 years
B．lived a shorter but better life than those born later
C．lived to 47 years of age
D．lived 27 years longer than those born in 1981
由原文最后一句It has increased from 47 years for those born in l900 to 74 years l981(寿命从1900年出生的人的47岁增长到1981年出生的人的74岁)可知C正确。