评论
打印
Passage 5
One of the most popular myths about the United States in the 19th Century was that of the free and simple life of the farmer. It was said that the farmers worked hard on their own land to produce whatever their families' needed. They might sometimes trade with their neighbors, but in general they could get along just fine by relying on themselves, not on commercial ties with others. This is how Thomas Jefferson idealized the farmer at the beginning of the 19th century. And at that time, this may have been close to the truth especially on the frontier. But by the mid century sweeping changes in agriculture were well under way as farmers began to specialize in the raising of crops such as cotton or corn or wheat. By late in the century revolutionary advances in farm machinery has vastly increased production of specialized crops and extensive network of railroads had linked farmers throughout the country to markets in the east and even overseas. By raising and selling specialized crops, farmers could afford more and finer goods and achieve a much higher standard of living but at a price. Now farmers were no longer dependent just on the weather and their own effort, their lives were increasingly controlled by banks, which had powder to grant or deny loans for new machinery, and by the railroads which set the rates for shipping their crops to market. As businessmen, farmers now had to worry about national economic depressions and the influence of world supply and demand on, for example, the price of wheat in Kansas. And so by the end of the 19th century, the era of Jefferson's independent farmer had come to a close.
Questions 16 to 19 are based on the talk in class about United States history.
16. What is the main topic of the talk?
17. According to the professor, what was the major change in agriculture during the 19th century?
18. According to the professor, what was one result of the increased use of machinery on farms in the United States?
19. According to the professor, why was world market important for the United States agriculture? Times大学排名Top10
Passage 6
The energy which the sun radiates goes in every direction. However, only a minute part of it falls on the earth. Even so, it represents the power of about five million horsepower per square mile per day. The sun gives us as much energy every minute as mankind uses in a year. At present, we use this energy indirectly, and it is our only final source of power. Coal represents the chemical action of the sun on green plants thousands of years ago. Water power results from the sun's creation vapor and the resulting rain. Even windmills operate because of air currents set in motion by the uneven heating effects of the sun in different places, Already, a scientist has worked out an engine, surprisingly efficient. This engine uses a series of mirrors which concentrate the sun's energy on a tube of water to create seam.
Questions 20 to 22 are based on the passage you've just heard.
20. What does this passage tell us about?
21. How much energy does the sun give to the earth in a minute?
22. How do people use solar energy at present?
