题目

对于质量守恒定律的解释不正确的是： A   化学反应前后，分子的数目不变   B   化学反应前后，原子的种类不变。 C   化学反应前后，原子的数目不变。 D   化学反应前后，参加反应的物质的总质量和生成物的总质量相等 答案：ADirections： Read the following passage. Complete the diagram by using the information for the passage. Write NO MORE THAN 3 WORDS for each answer. The contemporary environmental movement is often said to have begun with the publication of Silent Spring by the zoologist and biologist Rachel Carson (1907–1964). This landmark work, which took Carson 4 years to complete, diligently detailed the relationship between animal death  and the use— now understood as the abuse—of man-made chemicals used as pesticides, especially DDT. One of the claims of the book that she tried to demonstrate was that DDT had the effect of softening the eggshells of birds as well as interfering with their reproduction, and that such effects would lead to their extinction if use of DDT were to continue. It would eventually create a springtime of silence when the songs of birds would not be heard. Her studies also found DDT to be a cause of human cancers. Born in Springdale, Pennsylvania, Carson graduated from the Pennsylvania College for Women in Pittsburgh (now Chatham College), where she majored in English until her junior year, when a course in biology inspired her to switch to zoology as her field of concentration. She earned a master’s degree in this area from Johns Hopkins University and became a biologist at the Bureau of Fisheries in 1936. During this time, she wrote for various national magazines, and her first book, Under the Sea-Wind, was published. Carson had concerns as early as 1945 about pesticides being used more and more by the government. But her cautionary claims in Silent Spring were met with anger by the pesticide and chemical industries. Her authority as a scientist were challenged, and it was held that her findings were just the roars of a hysterical(歇斯底里的) woman. She was even accused of being a member of the Communist Party. Some go so far as to say that she told a lie . But She is often celebrated as the founder of the contemporary U.S. environmental movement. Yet her work in Silent Spring, warning about the misuse of pesticides and other chemicals, has not as yet taken firm hold. Americans likely use twice as much the volume of pesticides that they did at the time she published her seminal work, and globally, their use is ever increasing. Powerful pesticides are sold over the counter, and their use is so widespread that many environmentalists are fearful that chemical runoff into streams and rivers is still popullting the animals that humans eat and the water that they drink. In short, while the main purpose of Silent Spring was to warn the public of the dangers of the overuse of pesticides and chemicals, nonetheless the public hasn’t refused such use. Isn't it time that we firmly said no to pesticides?