Although the United States covers so much land and the land produces far more food than the present population needs，its people are by now almost entirely an urban society Less than a tenth of the people are engaged in agriculture and forestry(林业)，and most of the rest live in or around towns，small and large.Here the traditional picture is changing：every small town may still be very like other small towns，and the typical small town may represent a widely accepted view of the country，but most Americans do not live in small towns any more.Half the population now lives in some thirty metropolitan areas(1arge cities with their suburbs、of more than a million people each—a larger proportion than in Germany or England，let alone France.The statistics(统计)of urban and rural population should be treated with caution because so many people who live in areas classified as rural travel by car to work in a nearby town each day.As the rush to live out of town continues.rural areas within reach of towns are gradually filled with houses，so that it is hard to say at what moment a piece of country becomes a suburb But more and more the typical American lives in a metropolitan rather than a small town environment.
36.If now America has 250 million people.how many of them are engaged in agriculture and forestry?
A.About 25 million. B.More than 25 million.
C.Less than 25 million. D. Less than 225 million
37.Which of the following four countries has the smallest proportion of people living in metropolitan areas?
A.United States. B.Germany. C.France.D.England.
38.What’s the meaning of the word“metropolitan”in the middle of the passage?
A .Of a large city with its suburbs. B.Of small and large towns.
C.Of urban areas. D.Of rural areas.
39.According to the passage，what can we learn about small towns in the United States?
A Most small towns become gradually crowded B.Small towns are still similar to each other.
C.As the traditional picture is changing，towns are different. D .Small towns are turning into large cities
40.Why is it hard to say when a piece of country becomes a suburb?
A.Because they are the same. B.Because the rush takes place too quickly
C.Because the process is gradual. D.Because more and more Americans live in metropolitan areas.