问题 问答题 简答题

试述结核杆菌的染色、培养、致病物质及感染特点。

答案

参考答案:1、形态染色:菌体细长微弯,有分枝,排列不规则,多单个散在,易发生L型,抗酸染色阳性。

2、培养特性:专性需氧,温度37℃,pH偏酸6.5-6.8营养要求高,罗氏培养基(蛋黄、甘油、天门冬素、马铃薯、无机盐、孔雀绿等)生长缓慢,18h分裂一次,2-4W形成R型菌落,“菜花样菌落”,乳白色干燥不透明,表面呈颗粒结节,边缘不整

3、致病性:结核杆菌无侵袭性酶,不产生内、外毒素,其致病性主要由于细菌繁殖引起炎症;菌体成分;代谢产物毒性作用;抗体对菌体成分产生免疫病理损伤。

阅读理解

When a magazine for high school students asked its readers what life would be like in twenty years, they said: Machines would be run by solar power. Buildings would rotate(旋转)so they could follow the sun to take maximum advantage of its light and heat. Walls would “give light” and “change color with the push of a button.” Food would be replaced by pills. School would be taught by electrical impulse(电脉冲)while we sleep. Cars would have radar(雷达). Does this sound like the year 2000? Actually, this article was written in 1958 and the question was, “what will life be like in 1978?

The future is much too important to simply guess about, the way the high school students did, so experts are regularly asked to predict accuately. By carefully studying the present, skilled businessmen, scientists, and politicians are supposedly able to figure out in advance what will happen. But can they? One expert on Cities wrote: Cities of the future would not be crowded, but would have space for farms and fields. People would travel to work in “airbuses”, large all-weather helicopters carrying up to 200 passengers. When a person left the airbus station he could drive a coin-operated car equipped with radar. The radar equipment of cars would make traffic accidents “almost unheard of”. Does that sound familiar? If the expert had been accurate it would, because he was writing in 1957. His subject was “The city of 1982”.

If the professionals sometimes sound like high school students, it’s probably because future study is still a new field. But economic forecasting, or predicting what the economy will do, has been around for a long time. It should be accuate, and generally it is. But there have been some big mistakes in the field, too. In early 1929, most forecasters saw an excellent future for the stock market. In October of that year, the stock market had its worst losses ever, ruining thousands of investors who had put their faith in financial foreseers.

One forecaster knew that predictions about the future would always be subject to significant error. In 1957, H.J. Rand of the Rad corporation was asked about the year 2000, “Only one thing is certain,” he answered. “Children born today will have reached the age of 43.”

小题1:How many examples does the author offer to describe the future life?

A.Three

B.Four

C.Five

D.Six小题2:The high school students’ answers to “What would life be like in 1978?” sound __________.

A.accurate

B.imaginative

C.correct

D.foolish小题3:In the second paragraph, the writer gives examples to show _________.

A.predicting about the future can be done in a humorous way

B.no predictions are based on careful research

C.experts are always better than others in figuring out what the future will be like

D.forecasting the future is not an easy job even for experts in this field小题4:From the third paragraph we can learn that _________.

A.economy forecasting is rather a new field

B.experts began economy forecasting in 1929

C.the predictions about economic situation caused the investors to lose lots of money

D.good, accurate forecasting helped the stock market overcome the difficulties小题5:H.J.Rand’s prediction about the year 2000 shows that ________.

A.it is easy to figure out in advance what will happen

B.it is difficult to figure out in advance what will happen

C.only professionals can figure out in advance what will happen

D.very few professionals figure out in advance what will happen

选择题