问题 单项选择题

在A、B两组人群中进行筛选,假定筛选试验的灵敏度和特异度是已知的,A人群患病率为10%,B人群为1%,则下列哪种结论是正确的()。

A.A人群阳性结果者中假阳性者所占比例低于B人群

B.A人群阳性结果者中真阳性的比例低于B人群

C.A人群中可靠性高于B人群

D.A人群中特异度低于B人群

E.A人群中灵敏度高于B人群

答案

参考答案:A

填空题
阅读理解

A euphemism (from the Greek words eu—well and pheme—speak) is a word or expression that is used when people want to find a polite or less direct way of talking about difficult or embarrassing topics like death or the bodily functions.Most people,for example,would find it very difficult to say in plain language that they have arranged for their sick old dog to be killed.They would soften the pain by saying:We had Ruby put down or We had Ruby put to sleep.Many people prefer to call someone plain than ugly,or cuddly rather than fat.

Euphemisms are an important part of every language,but it seems that English has an ever­growing number of them.The non­native speaker not only has to make sense of the euphemisms he hears,he also has to learn which euphemisms are appropriate in any particular situation.He might be aware that his American friend needs to use the toilet when she asks where the bathroom (or restroom,or comfort station) is,but he is less likely to guess that his English friend has the same need when he says he has to see a man about a dog.He might have learned,for example,that in the family way is a euphemism for pregnant.If,however,he says to his boss,“Congratulations!I hear your wife is in the family way,” he would be using an expression that is too familiar for the circumstances.

Schools are full of euphemisms.At Frankfurt International School,for example,the special lessons given to students who are having difficulties in their school subjects are called Study Center (in the middle school) and Academic Workshop (in the high school).Teachers rightly do not want to upset students or parents by being too frank or straightforward,and usually choose a softer word or expression to convey the same message.

小题1:According to the passage,people use euphemisms in order to________.

A.make themselves understood

B.avoid embarrassment

C.to sound straightforward

D.attract attention小题2:A person who is described as plain and cuddly is in fact________.

A.tall and handsome 

B.pretty and slim

C.ugly but tall 

D.ugly and fat小题3:When an English lady says she has to see a man about a dog,she might want to________.

A.have her old dog killed 

B.see an ugly friend

C.go to the toilet

D.see a pregnant woman小题4:The main purpose of Paragraph 2 is to________.

A.stress that euphemisms are an important part of every language

B.inform readers that English has an ever­growing number of euphemisms

C.suggest non­native speakers use euphemisms as often as possible

D.warn English learners to be careful about the meaning and use of euphemisms小题5:At Frankfurt International School,the students who receive lessons in Study Center________.

A.have poor grades in the subjects

B.do well in school

C.work hard at their lessons

D.prefer to learn more