The population of many Alaskan cities has ______ doubled in the past three years.A.larger
The population of many Alaskan cities has ______ doubled in the past three years.
A.larger than
B.more than
C.as great as
D.as many as
The population of many Alaskan cities has ______ doubled in the past three years.
A.larger than
B.more than
C.as great as
D.as many as
Some people believe that population control in developed countries may______.
A.increase market demand
B.lower unemployment rate
C.slow down economic growth
D.create more job opportunities
Development and the Protection of Environment
Modern technology has developed in a manner which often conflicts with the environment. The many industrial pollutants constantly impact the environment in a harmful way. Nevertheless, it is possible and practical to achieve a high level of technology, with- out altering the overall natural environment.
There are two basic methods of conserving the natural environment. One is alternative technology in which techniques (such as windmills and solar energy) must be found for providing power. The other is to try to minimize the, effects of modern technology by the more efficient: use of materials and more, effective pollution control.There comes a point when the quality of life can no longer be, improved because of the high population density and the largely unsuccessful attempts to meet its demands.
Present energy policies of the western world are considering new energy sources to meet the demands of a growing population. The main Sources used have been oil, gas, and coal-which are in limited supply-- and nuclear power, which has problems concerning radioactive waste storage. Wind and solar energy are alternative possibilities, but only solar energy is likely to become a main power source for many countries.
Many of the materials used daily in a technological society are destined to be discarded, Rags, paper, metal, glass, and plastics are all substances that could be recycled or reuseD.Research is being done to determine methods of separating useful products from industrial and domestic waste.
The processing of sewage is also helpful. This is collected in gasholders and burned to produce heat and create electricity. The waste itself is often used for soil enrichment.
第 41 题 Modern technology is harmful to the natural environment mainly because
A.of industrial pollutants
B.it has become too expensive
C.it has become too complicated
D.it consumes all natural resources
Labor Force
The labor force is the part of a nation's population that works for pay or that is looking for a paying job. In 1800, the United States had about 2 million people in its labor force. Most of them worked on farms, most of whom were men. In 1993, about 130 million Americans were in the labor force. 96 million workers were found in large cities, 46 percent of whom were women.
New Kinds of Jobs
In the twentieth century, the U. S. labor force has undergone many changes. One of the most significant of these changes is in the decline in the number of blue collar jobs and the rise in the number of white-collar jobs.
A blue-collar job involves manual or outdoor labor. Blue-collar workers include factory assemblers and welders; carpenters, plumbers(水暖工), mechanics, and painters; construction workers, and truck drivers. Although the number of blue-collar workers increased in the twentieth century, the future will see a declining need for such workers. Some of their jobs will be taken over by advanced automated and computerized machinery that can do certain blue-collar jobs more quickly and efficiently than people can. In contrast, a white-collar job involves work that is not chiefly manual. For example, white collar workers include accountants, engineers, teachers, lawyers, and sales personnel. In 1900, white collar workers made up about 20 percent of the labor force; today, 67 percent of all American wage earners hold white collar jobs. Advances in computer technology have created many new white-collar jobs, such as those in programming and information processing. These changes will continue to dramatically change the nature of existing jobs.
The Rise of Women in the Labor Force
Until 1940, the opportunities for women to hold jobs were limited. Prejudice and discrimination(歧视)against women forced many of them to find employment as teachers, nurses, and secretaries. In 1940, women held only 25 percent of the jobs.
World War Ⅱ-1941 through 1945-brought about many changes in the labor force. Men were drafted to serve in the armed forces of the United States. At the same time, the country needed labor to keep factories running at full production to support the war effort. As a result, women were suddenly needed and hired even though they had been previously excluded from such jobs. Women not only repaired airplanes and land vehicles, but they also drove trucks, operated radios and ma chinery, and did clerical work.
During the war years, the percentage of women in the labor force rose from 25 percent to 35 percent. Married women, many of whose husbands were in the armed forces, made up the greatest number of new women workers. In 1940, fewer than half of working women were single, but by 1945 a majority of women workers were married. By the end of the war, one out of every three workers in industry and business was a woman.
The Postwar Years
After the war, the men who returned from the armed forces went back to the same jobs they had held prior to the war. As a result, many women lost their wartime jobs. However, not all the women who had held jobs for the first time returned to their former roles as homemakers. Women had proved they could do these jobs well. As a result, the traditional barriers against the employment of women in such industries as steel and shipbuilding started to disappear. As the postwar prosperity continued, new positions became available for the returning men and for the many women workers now in the labor force.
Many women found that they enjoyed not only employment outside their homes but also the benefits of paying jobs. Many women were beginning to see work as a permanent part of their lives. By earning their own income, they became less dependent and more self-sufficient. Their independence gave them new choices and made them aware of a wider range of roles a
A.Y
B.N
C.NG
A—overpopulation B—under population
C—working population D—population waiting for employment
E—urban population F—rural population
G—population reproduction H—population increase
I—population decrease J—population base
K—population distribution L—population density
M—population quality N—population pyramid
O—population statistics P—population theory
Q—population studies
51. ()在业人口 ()人口密度
52. ()人口增长 ()人口年龄金字塔
53. ()城市人口 ()人口质量
54. ()人口理论 ()人口分布
55. ()待业人口 ()人口过剩
There is a rapid increase in population in that country that has caused a food (short) ______.
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