题目

用液态二氧化碳灭火器扑灭图书失火的原理是 A．清除可燃物  B．降低图书的着火点  C．隔绝空气  D．． 答案：考点：灭火的原理和方法． 专题：化学与生活． 分析：根据已有的知识进行分析解答，液体二氧化碳气化能隔绝氧气且能降低温度到着火点以下，据此解答． 解答：解：液体二氧化碳气化能隔绝氧气且能降低温度到着火点以下，故填：C，降低温度到可燃物的着火点以下． 点评：本题考查的是灭火 阅读理解(Reading Comprehension) 　　Generations of Americans have been brought up to believe that a good breakfast is necessary for their life．Eating breakfast at the start of the day, we have all been told and told again, is as necessary as putting gas in the family car before starting a trip． 　　But for many people the thought of food as the first thing in the morning is by no means a pleasure．So despite(尽管)all the efforts, they still take no breakfast．Between 1977 and 1983, the latest year for which figures are available(可得到的)，the number of people who didn't have breakfast increased by 33 percent from 8.8 million to 11.7 million－according to the Chicago-based Market Research Corporation of America． 　　For those who feel pain or guilty(内疚的)about not eating breakfast, however, there is some good news．Several studies in the last few years show that, for adults especially, there may be nothing wrong without having breakfast．“Going without breakfast does not affect performance, ”said Arnold E．Bender, former professor of nutrition at Queen Elizabeth College in London, “nor does giving people breakfast improve performance．” 　　Scientific evidence linking breakfast to better health or better performance is surprisingly not proper, and most of the recent work relates to children, not adults．“The literature, ”says one researcher, Dr．Ernesto Pollitt at the University of Texas, “is poor”． (1) The latest year for which figures could be obtained is ________． [　　] A． the year the author wrote the article B． 1977 C． the year between 1977 and 1983 D． 1983 (2) For those who do not take breakfast, the good news is that ________． [　　] A． several studies have been done in the past few years B． the omission of breakfast does no harm to one's health C． adults have especially made studies in this field D． eating little in the morning is good for health (3) “…．nor does giving people breakfast improve performance”means ________． [　　] A． anyone without breakfast does improve his performance B． not giving people breakfast improve performance C． having breakfast does not improve performance, either D． people having breakfast do improve their performance, too (4) The word“literature”in the last sentence refers to ________． [　　] A． stories, poems, plays, etc． B． written works on a particular subject C． any printed material D． the modem literature of America (5) What is implied but not stated by the author is that ________． [　　] A． breakfast does not affect performance B． Dr．Pollitt is engaged in research work at an institution of higher learning C． not eating breakfast might affect the health of children D． Professor Bender once taught college course in nutrition in London