Farming was once the chief way of life in nearly every country. People cannot live without food, and nearly all their food comes from crops and animals raised on farms. Not many people farm for a living any more, but farming remains the most important work in the world.
Before the nineteenth century, the typical American family lived on a small farm. They raised pigs, cattle, sheep, chickens, and planted corn, fruits, garden vegetables, and wheat. Everyone worked long and hard, but the results were often poor. Families barely harvested enough food for themselves. This situation began to change during the last half of the 1800's and it changed remarkably(明显地) in the next century.
Scientific methods and labor-saving machinery(机械）have made farming increasingly productive. The development of improved plant varieties and fertilizers（肥料）has helped double and even triple the production of some major crops. More scientific animal care and animal raising have helped increase the amount of meat and products that animals produce. At the same time, the use of tractors and other modern farm equipment has sharply reduced the need for farm labor.
As farming has become less important as a way of life in the United States, it has become more important as a source which offers materials to industry. Today's successful farmers are experts not just in agriculture but also in accounting, marketing, and finance. Farms that are not run in a similar way have great difficulty surviving.   
We are told in the first paragraph about ____.

A．the history of farming	B．the importance of farming
C．the development of farming	D．the changes of farming

Which of the following describes American farming before the 19th century?

A．Farmers didn’t work hard on their farms.
B．Farmers used tractors to help them.
C．Farming was the main way of living for most people	D．Farmers could supply materials to industry.

The passage mainly talks about_____.

A．the advantages of American farming	B．the changes in American farming
C．the situation of American farms	D．how rapidly farming has developed