标题: 重问大全-9-19 [打印本页] 作者: joywzy 时间: 2003-5-2 19:42 标题: 重问大全-9-19 19. In 1987 sinusitis was the most common chronic medical condition in the United States, followed by arthritis and high blood pressure, in that order. The incidence rates for both arthritis and high blood pressure increase with age, but the incidence rate for sinusitis is the same for people of all ages. The average age of the United States population will increase between 1987 and 2000.
Which of the following conclusions can be most properly drawn about chronic medical conditions in the United States from the information given above? (A) Sinusitis will be more common than either arthritis or high blood pressure in 2000. (B) Arthritis will be the most common chronic medical condition in 2000. (C) The average age of people suffering from sinusitis will increase between 1987 and 2000. (D) Fewer people will suffer from sinusitis in 2000 than suffered from it in 1987. (E) A majority of the population will suffer from at least one of the medical conditions mentioned above by the year 2000.
答案：C
题干中the incidence rate for sinusitis is the same for people of all ages.不是与C矛盾吗？我选了D，用的是排除法，排除了A，B，C，E。
原文重点的句子就是"the incidence rate for sinusitis is the same for people of all ages", 相当于我举的例子中的两人, 既在各个年龄层的比例相同.作者: 1stzhang 时间: 2003-5-2 22:10
这个题目可以这样理解： s在前 arthritis and high blood pressure 在后 后面的age增加， s的age也增加。作者: cranberry 时间: 2003-5-2 22:21
严重同意zhang,我们确定的只是人的平均年龄会增加，但顺序不是完全肯定，但S的比率不变，所以得S的平均年龄就增加了作者: joywzy 时间: 2003-5-2 23:02
总算明白了，非常感谢!!!