四、首段原则 首段原则应用于根据首段内容所设置的题目，它包括两种形式：首句原则和末句原则。 1.首句原则 回顾近几年的考研阅读题，细心的考生会发现历年考研试卷中都有题目针对首段第一句话设问，为什么会出现这种情况？原因很简单，考研阅读所选的文章均是议论文和说明文，此类文章的文体要求在首段提出观点、突出中心，因此第一段就好像全篇文章的一个总纲，确定了文章的主要内容，而第一句话常常是一个自然段的主题句，首段首句自然就成为常考且必考的一个考点。来源：www.examda.com 例 it is said that in england death is pressing， in canada inevitable and in california optional. small wonder. americans life expectancy has nearly doubled over the past century. failing hips can be replaced， clinical depression controlled， cataracts removed in a 30_minute surgical procedure. such advances offer the aging population a quality of life that was unimaginable when i entered medicine 50 years ago. but not even a great health_care system can cure death—and our failure to confront that reality now threatens this greatness of ours. what is implied in the first sentence？ [a]americans are better prepared for death than other people. [b]americans enjoy a higher life quality than ever before. [c]americans are over_confident of their medical technology. [d]americans take a vain pride in their long life expectancy.[2003年56题] c[正确答案] 2.末句原则 有时一个自然段的主题句也会出现在段末，因此考点也相应转向末句。 例 technically， any substance other than food that alters our bodily or mental functioning is a drug. many people mistakenly believe the term drug refers only to some sort of medicine or an illegal chemical taken by drug addicts. they dont realize that familiar substances such as alcohol and tobacco are also drugs. this is why the more neutral term substance is now used by many physicians and psychologists. the phrase“substance abuse”is often used instead of“drug abuse”to make clear that substances such as alcohol and tobacco can be just as harmfully misused as heroin and cocaine. “substance abuse”is preferable to“drug abuse”in that. [a]substance can alter our bodily or mental functioning if illegally used [b]“drug abuse”is only related to a limited number or drug takers [c]alcohol and tobacco are as fatal as heroin and cocaine [d]many substances other than heroin or cocaine can also be poisonous[1997年59题] d[正确答案]