问题 单项选择题

关于实验流行病学与观察流行病学的区别,以下说法正确的是()。

A.研究对象是随机样本

B.由研究者决定哪一组暴露于可疑危险因素,哪一组作为对照组

C.研究是前瞻性的

D.研究对象分为暴露组和非暴露组

E.暴露组和非暴露组的基本特征相似

答案

参考答案:B

解析:本题的主要考试要点为实验流行病学的原理和特征。与观察性研究相比较,实验流行病学的关键不同点是随机分组、暴露因素是研究者为了实现研究目的而施加于研究对象的。因此,答案为B。

阅读理解

阅读理解。

     Depression (抑郁症) is a serious problem today. Depression causes workers to be unproductive, causing

companies and countries to lose billions of dollars. One expert says that depression is like cancer because it is

"widespread,costly and deadly". Depression hits one person in five around the world.

     Although people have believed depression to be a problem among the rich and educated, studies show that

depression is a problem among everyone. Over any six-month period, between five to seven percent of the

world's population will be suffering from a serious depression.

      Suicide (自杀) rates among people suffering from the disease in its extreme,or clinical form were 80

percent higher than in the population at large, and sufferers were four times more likely to have heart attacks.

People who suffer from depression often have problems sleeping,getting upon time, and doing work

productively. 

      Depression,which researchers agree has its origin in the genes (基因), brings loss of confidence and

ability to concentrate-making it impossible for employees and managers to work efficiently.

     Depression is made more serious in China by Chinese's inability to face it.Many people believe that

depressed people are either weak or lazy. Besides, there is no good treatment,with few specialists available.

      "Most patients in China just don't get help, "a Chinese doctor says."In my hospital.I have to see 30 or 40

patients in a morning,just have time to say "Hello how do you feel?"

      In Western countries,people are not afraid to admit that they have depression,but most do not tell it to their

boss,because they fear that their boss would fire them.

      "In my experience, aging bosses are the most willing to admit they have it. Because they feel the most

secure about themselves,"an American doctor says.

     Hopefully,in the near future,people around the world will be able to admit that they have depression so that

they can get the right treatment.

1. Which of the following is true according to the passage?

A. It is widely believed that everyone may suffer from depression.

B. Depression brings great problems to its sufferers in their life and work

C. Depression is a commonly-existing problem only in rich countries.

D. The poorer and the less educated a person is,the less he will suffer from depression.

2. Compared to normal people,the depressed people are likely to be _____.

A.very unconfident and often absent-minded

B. easy to avoid being hit by heart attacks

C. working efficiently and productively

D. either weak or lazy

3. Depression becomes more serious in China because of _____.

A. the understanding of the problem

B. the lack of treatment and doctors

C. their unwillingness to tell it to their boss

D. the doctors' careless work

4. What can we infer from the passage?

A. People are suffering from depression because of the shortage of specialists.

B. The aging bosses around the world dare to say they are depressed.

C. More and more patients will turn to specialists for help.

D. Western people are braver than Chinese people.

问答题