Passage Three
The differences in living standards around the world are vast．In 1993，the average American
had an income of about$25，000.In the same year，the average Mexican earned$7，000，and the
average Nigerian camed$1，500,Not surprisingly，this large variation in average income is reflected in various measures of the quality of life．Changes in living standards over time are also
1arge． In the United States，incomes have historically grown about 2 percent per year(after
adjusting for changes in the cost of living)．At this rate，average income doubles every 35years．In
some countries，economic growth has been even more rapid． In Japan， for instance， average
income has doubled in the past 20 years，and in South Korca it has doubled in the past 10years．
What explains these 1arge differences in 1iving standards among countries and over time?
The answer is surprisingly Simple． A1most a11 variation in 1iving standards is attributable to
differences in countries’productivity-----that is， the amount of goods and services produced from each hour of a worker's time．In nations where workers can produce a large quantity of goods and services per unit of time，most people enjoy a high standard of living； in nations where workers are less productive，most people must endure a more meager existence．Similarly，the growth rate of a nation's productivity determines the growth rate of its average income．
The fundamental relationship between productivity and living standards is simple，but its implications are far-reaching．If productivity is the primary determinant of livings standards，other
explanations must be of secondary importance．For example，people might think that labor unions
or minimum-wage 1aws contributed to the rise in 1iving standards of American workers over the past century. Yet the real hero of American workers is their rising productivity．
The relationship between productivity and living standards also has great implications for public po1icy．When thinking about how any policy will affect living standards， the key question is how it will affect our ability to produce goods and services．To improve living standards，po1icy makers need to raise productivity by ensuring that workers are well educated，have the too1s needed to produce goods and services，and have access to the best available technology．

46．Which of the following countries has enjoyed the fastest economic growth in history?
A．Mexico． B．The United States ．
C．Japan． D．South Korea ．

47．The word“meager”in the second paragraph is closest in meaning to“__________”．
A． modest B． poor C． meaning less D． plentiful

48．What is the most important factor that leads to the rise in living standards of average people?
A．Labor unions． B．Minimum-wage laws ．
C．Rising productivity． D．Favorable publicpo1icy．

49．The study of the relationship between productivity and 1iving standards is significant in that_________．
A．it calls po1icy makers’attention to a qualified work force
B．it encourages workers to get better education.
C．it helps improve the workers’ability to produce goods and services
D．it enables policy makers to access the latest technology

50．The passage mainly discusses____________
A．the differences in average income among countries
B．the relationships between productivity and living standards
C．th causes of the rise in living standards
D．the importance of raising productivity.