13. Emissions from automobiles that burn gasoline and automobiles that burn diesel fuel are threatening the quality of life on our planet, contaminating both urban air and global atmosphere. Therefore, the only effective way to reduce such emissions is to replace the conventional diesel fuel and gasoline used in automobiles with cleaner-burning fuels, such as methanol, that create fewer emissions. Which one of the following is an assumption on which the argument depends? (A) Reducing the use of automobiles would not be a more effective means to reduce automobile emissions than the use of methanol. (B) There is no fuel other than methanol that is cleaner-burning than both diesel fuel and gasoline. (C) If given a choice of automobile fuels, automobile owners would not select gasoline over methanol. (D) Automobile emissions constitute the most serious threat to the global environment. (E) At any given time there is a direct correlation between the level of urban air pollution and the level of contamination present in the global atmosphere. 答案A, 做题时感觉应该是它, 可是注意到原文划线部分是本文结论部分,其中的the only effective觉得在A中找不到很好的assumption对应, 如果把only改成most, 那么答案A我就能理解了.不知道我这么理解对不对?
Despite improvements in treatment for asthma, the death rate form this disease has doubled during the past decade from its previous rate. Two possible explanations for this increase have been offered. First, the recording of deaths due to asthma has become more widespread and accurate in the past decade than it had been previously. Second, there has been an increase in urban pollution. However, since the rate of deaths due to asthma has increased dramatically even in cities with long-standing, comprehensive medical records and with little or no urban pollution, one must instead conclude that the cause of increased deaths is the use of bronchial inhalers by asthma sufferers to relieve their symptoms. Which one of the following is an assumption on which the argument depends? (A) Urban pollution has not doubled in the past decade. (B) Doctors and patients generally ignore the role of allergies in asthma. (C) Bronchial inhalers are unsafe, even when used according to the recommended instructions. (D) The use of bronchial inhalers aggravates other diseases that frequently occur among asthma sufferers and that often lead to fatal outcomes even when the asthma itself does not. (E) Increased urban pollution, improved recording of asthma deaths, and the use of bronchial inhalers are the only possible explanations of the increased death rate due to asthma.
如果按照取非的思路, 我倒觉得B答案更适合这道题: b) there is no fuel other than methanol that is cleaner-burning than both diesel fuel and gasoline. 取非的话, 变成: 除了methanol之外, 还有其他的fuel比diesel 和gasoline燃烧更清洁. 这样,正好否定了原文结论:the only effective way is methanol. 请大家讨论......
而八戒GG的题目, 我还是觉得E对. 原文在否定了两种可能的解释之后, must得出第三种解释, 为了满足must的要求,就必须只有这三种解释, E答案. 而答案(B) Doctors and patients generally ignore the role of allergies in asthma.说他是原文逻辑的weaken会比较合适. 因为忽略了另外的可能性,所以原文结论不成立.
以下是引用rabbitbug在2003-12-26 18:55:00的发言: 而八戒GG的题目, 我还是觉得E对. 原文在否定了两种可能的解释之后, must得出第三种解释, 为了满足must的要求,就必须只有这三种解释, E答案. 而答案(B) Doctors and patients generally ignore the role of allergies in asthma.说他是原文逻辑的weaken会比较合适. 因为忽略了另外的可能性,所以原文结论不成立.
第一题我认为B 不好,因为in automobiles with cleaner-burning fuels, such as methanol, that create fewer emissions。这里面methanol 仅是一个例子。注意用的是such as. 如果题目是用only methanol,或是去掉such as .则B 对。指出唯一性。