17. Since 1945 there have been numerous international confrontations as tense as those that precipitated the Second World War, and yet no large-scale conflict has resulted. To explain this, some argue that fear of enormous destruction such as the Second War produced has had a dramatic deterrent effect. Which of the following, if true, most seriously weakens the deterrent theory mentioned above?
(A) After the First World War, the fear of great future destruction was as intense as it was after the Second World War. (B) Psychologists have determined that the fear of retaliation tends to temper aggressiveness among human beings. (C) The Second World War was far less distractive than most people generally believe. (D) Fear of repeating the levels of destruction that the Second World War produced is as pervasive today as it was forty years ago. (E) Many of the international confrontations that have occurred since 1945 have involved countries that participated in the Second World War. 请问为什么不选c 20. The number of people diagnosed as having a certain intestinal disease has dropped significantly in a rural county this year, as compared to last year. Health officials attribute this decrease entirely to improved sanitary conditions at water-treatment plants, which made for cleaner water this year and thus reduced the incidence of the disease. Which of the following, if true, would most seriously weaken the health officials' explanation for the lower incidence of the disease? (A) Many new water-treatment plants have been built in the last five years in the rural county. (B) Bottled spring water has not been consumed in significantly different quantities by people diagnosed as having the intestinal disease, as compared to people who did not contract the disease. (C) Because of a new diagnostic technique, many people who until this year would have been diagnosed as having the intestinal disease are now correctly diagnosed as suffering from intestinal ulcers. (D) Because of medical advances this year, far fewer people who contract the intestinal disease will develop severe cases of the disease. (E) The water in the rural county was brought up to the sanitary standards of the water in neighboring counties 10 years ago. 请帮忙解释一下B选项 |