标题: 丁丁倒数 68# [打印本页] 作者: 玛莎丁丁 时间: 2012-8-1 23:41 标题: 丁丁倒数 68# A new government policy has been developed to avoid many serious cases of influenza. This goal will be accomplished by the annual vaccination of high-risk individuals: everyone 65 and older as well as anyone with a chronic disease that might cause them to experience complications from the influenza virus. Each year’s vaccination will protect only against the strain of the influenza virus deemed most likely to be prevalent that year, so every year it will be necessary for all high-risk individuals to receive a vaccine for a different strain of the virus.
Which one of the following is an assumption that would allow the conclusion above to be properly drawn?
(A) The number of individuals in the high-risk group for influenza will not significantly change from year to year. (B) The likelihood that a serious influenza epidemic will occur varies from year to year. (C) No vaccine for the influenza virus protects against more than one strain of that virus. (D) Each year the strain of influenza virus deemed most likely to be prevalent will be one that had not previously been deemed most likely to be prevalent. (E) Each year’s vaccine will have fewer side effects than the vaccine of the previous year since the technology for making vaccines will constantly improve.
This is a question from June 2007 preptest (Section 2). It turned out that most mistakes I made could have been avoided by carefully reading the choices. This is the only one worth some reflection I guess. Share with you guys. OA is D and C could be temping at first sight.作者: 玛莎丁丁 时间: 2012-8-1 23:44
【Here is explanation for reference】
Question Type: Assumption Each year’s vaccination will protect only against the strain of the virus deemed most likely to be prevalent that year, so high-risk individuals will need to receive a vaccine for a different strain each year. Doesn’t this assume that the prevalent strain of the virus will change every year? Take, for example, a hypothetical scenario in which last year’s prevalent flu strain was the same as this year’s. High-risk individuals would thus be getting the same vaccination this year that they got last year. In order to conclude that people will get vaccinated for a different strain each year, the author must assume that the flu strain will change each year. Answer (D) correctly expresses this assumption. (A) is out of scope. The number of vaccinations given is not at issue. (B) is out of scope. The likelihood of an outbreak is irrelevant. (C) is tempting, but notice the language in the passage: the annual vaccination will protect against just one strain – the one deemed most likely to be prevalent that year. Thus, the fact that no vaccine protects against multiple strains is a moot point. (E) is out of scope (side effects?).