问题 单项选择题

研究某一有毒物质对作业工作的健康危害时,发现暴露于该有毒物质者的死亡率反而比一般人群低。原因是接触此类有毒物质者,由于工作性质的需要,其健康水平就比一般人群高因而对某些疾病的易感性低所致。导致上述研究结果中毒物与健康之间虚假联系的原因是

A.排除偏倚
B.易感性偏倚
C.混杂偏倚
D.信息偏倚
E.报告偏倚

答案

参考答案:B

阅读理解

阅读理解

     Taiwan police cannot decide whether to treat it as an extremely eleven act of stealing or an even

cleverer cheat  Either way , it could be the perfect crime, because the criminals are birds-horning pigeons !

     The crime begins with a telephone message to the owner of a stolen car : if you want the car back,

pay up then, the car owner is directed to a park, told where to find a bird cage and how to attach money

to the neck of the pigeon inside . Carrying the money in a tiny bag , the pigeon flies off .

     There have been at least four such pigeon pick-ups in Changwa. What at first seemed like the work

of a clever stay-at-home car thief, however , may in face be the work of an even lazier and more

inventive criminal mind-one that avoid not only colleting money but going out to steal the car in the first

place . Police officer Chen says that the criminal probably has pulled a double trick: he gets money for

things he cannot possibly return . Instead of stealing cars , he lets someone else do it and then waits for

the car-owner to place an ad. in the newspaper asking for help .

     The theory is supported by the fact that , so far , none of the stolen cars have been returned . Also,

the amount of money demanded-under 3,000 Taiwanese dollars -seems too little for a car worth many

times more .

     Demands for pigeon-delivered money stopped as soon as the press reported the story. And even if

they start again, Chen holds little hope of catching the criminal . "We have more important things to do, "

he said .

1. The "lazier and more inventive" criminal refers to          .

A. the car thief who stays at home      

B. one of those who put the ads in the paper

C. the owner of the pigeons        

D. one of the policemen in Changwa  

2. After the car owner received a phone call. He         

A. gave the money to the thief and had his car back in a park

B. sent some money to the thief by mail

C. told the press about it

D. went to a certain pigeon and put some money in the bag it carried

3 . The writer mentions the fact that "none of the stolen cars have been returned" to show      .

A. how easily people get fooled by criminals        

B. the thief is extremely clever                

C. the money paid is too little                    

D. what Chen thinks might be correct

4. We may infer from the text that the criminal knows how to reach the car owners because  __  .

A. he lives in the same neighborhood        

B. he has seen the car owners in the park

C. he reads the ads in the newspaper          

D. he has trained the pigeons to follow them

5. The underlined word "they" in the last paragraph refers to          .

A. criminals            

B. pigeons      

C. the stolen cars    

D. demands for money

判断题