问题 单项选择题

从疾病生态学的角度来看;与疾病发生有关的三大因素是

A.病人、病原携带者、非病人

B.遗传、营养、身体锻炼

C.易感性、传播途径、病原物

D.宿主、环境、病原物

E.理化因素、生物学因素、社会经济因素

答案

参考答案:D

解析:19世纪末,人们在同疾病长期斗争过程中逐步总结出:疾病必须要有病原物、宿主及环境三个要素以及这三个要素的协同作用才可能发生。人们习惯用一个等边三角形来图示三者的关系,病原物、宿主(机体)及环境各占一个角。因此,人们称其为病因三角模型,或称之为流行病学三角。三角模型强调宿主和环境在疾病发生过程中的作用。并月.说明病原物、宿主及环境三个要素任何一方发生变化都会打破平衡引起疾病。该模型的缺点是对三个要素等量齐观,而且不适用于研究慢性病和非传染病的病因,因为它们往往并无特异性病原物存在。

阅读理解

阅读理解。

    There have been many great inventions or things that changed the way we live. The first great invention

was the one that is still very important today--the wheel. This made it easier to carry heavy things and to

travel long distance.

    For hundreds of years after that there were few inventions that as much effect as the wheel. Then in the

early 1800s the world started to change. There was little unknown land left in the world. People didn't have

to explore much any more. They began to work instead to make life better.

    In the second half of the 19th century many great inventions were made. Among them were the camera,

the light and the radio. These all play a big part in our daily life today.

    The first part of the 20th century saw more great inventions. The helicopter in 1909, movies with sound

in 1926, the computer in 1928, jet planes in 1930. This was also a time when a new material was first made.

Nylon came out in 1935. It changed the kind of clothes people wore.

    The middle part of the 20th century brought new ways to help people get over diseases. They worked

very well. They made people healthier and allowed them to live longer. By the 1960s most people could expect

to live to be at least 60.

     By this time most people in developed countries had a very good life. Of course new inventions continued

to be made. But man now had a desire (渴望) to explore again. The earth was known to man but the stars

were not. Man began looking for ways to go into space. Russia made the first step. Then United States took

a step. Since then other countries, including China and Japan, have made their own steps into space.

    In 1969 man took his biggest step away from earth. Americans first walked on the moon. This is certainly

just a beginning, though. New inventions will some day allow us to do things we have never yet dreamed of.

1. This passage talks mainly about            . [ ]

A. why cars were very important

B. when light was invented

C. how inventions affect people's daily life

D. which country made the first step into space

2. According to the passage man didn't have a desire to explore a lot            .[ ]

A. at the beginning of 1800s

B. in the 1960s

C. since the 1900s

D. from the 1800s to 1960s

3. In the 1800s, people began to work in order to make            .[ ]

A. explorations

B. their life better

C. discoveries

D. a trip to space

4. Nylon came out of five years later than            . [ ]

A. radio

B. camera

C. jet planes

D. movies

5. People can live longer lives because             that help cure diseases have worked very well. [ ]

A. doctors

B. new ways

C. medicines

D. new hospitals

单项选择题