资料分析

　　

　　Although we already know a great deal about influenza, and although the World Health Organization is constantly collecting detailed information from its chain of influenza reference laboratories throughout the world, it is extremely difficult for epidemiologists (流行病专家), who study infectious disease, to predict when and where the next flu epidemic will occur, and how severe it will be.

　　

　　There are three kinds of influenza virus, known as A, B and C. Influenza C virus is relatively stable and causes mild infections that do not spread far through the population. The A and B types are unstable, and are responsible for the epidemics that cause frequent concern. Following any virus attack, the human body builds up antibodies which confer immunity to that strain of virus, but a virus with the capacity to change its character is able to by-pass this protection. Variability is less developed in the influenza B virus, which affects only human beings. An influenza B virus may cause a widespread epidemic but will have little effect if introduced into the same community soon afterwards, since nearly everyone will have built up antibodies and will be immune. The influenza A virus, which affects animals also, is extremely unstable and is responsible for some of the worst outbreaks of the disease, such as the unparalleled pandemic, or world epidemic, of 1918-1919, when about half the world's population were infected and about twenty million people died, some from pneumonia caused by the virus itself and some from secondary complications(并发症) caused by bacteria.

　　

　　Accurate prediction is difficult because of the complication of the factors. A particular virus may be related to one to which some of the population have partial involved immunity. The extent to which it will spread will depend on factors such as its own strength, or virulence, the ease with which it can be transmitted and the strength of the opposition it encounters. Scientists, however, have a reliable general picture of the world situation. Influenza A attacks us in waves every two or three years, while influenza B, which travels more slowly, launches its main assaults every three to six years. The outbreaks vary from isolated cases to epidemics involving a tenth or more of the population. We may confidently prophesy that sooner or later large numbers of people will be feeling the unpleasant effects of some kind of influenza virus.

　　

　　1. Which of the following is the most appropriate title for the passage?

　　

　　A. Symptoms of Influenza

　　

　　B. Man Versus Virus

　　

　　C. World Health Organization: Forefront against Influenza Virus

　　

　　D. Variability of Influenza Virus

　　

　　2. According to the author, which of the following is NOT true about influenza?

　　

　　A. Man has obtained a great deal of knowledge about influenza.

　　

　　B. The occurrence of influenza is still unpredictable.

　　

　　C. Influenza is being studied extensively and systematically in many countries in the world under the guidance of World Health Organization.

　　

　　D. No reliable treatment of influenza has yet been found.

　　

　　3. What does the author say about the influenza B virus?

　　

　　A. B virus is relatively stable and causes mild infections that do not spread far through the population.

　　

　　B. B virus is unstable, and is responsible for the epidemics that cause frequent concern.

　　

　　C. B virus is extremely unstable and is responsible for some of the worst outbreaks of the disease.

　　

　　D. B virus has a very developed variability, and it affects only human beings.

　　

　　4. Which of the following is the most dangerous virus according to the passage?

　　

　　A. influenza A virus

　　

　　B. influenza B virus

　　

　　C. influenza C virus

　　

　　D. it cannot be determined by the information provided

　　

　　5. What does the word “assault” in the eighth line of the last paragraph mean?

　　

　　A. influence B. attack C. symptom D. damage

　　

　　6. Which of the following is NOT mentioned as a factor contributing to the extent to which a virus spreads?

　　

　　A. the strength of the virus

　　

　　B. the strength of the opposition the virus encounters

　　

　　C. the ease with which the virus can be transmitted

　　

　　D. the immunity the virus can induce

　　

　　单项选择

　　

　　7. It would be difficult for anyone to behave in a _____way when one is in a furious state.

　　

　　A. rational B. legal C. stable D. credible

　　

　　8. The final exams approached, _____the students became more and more nervous.

　　

　　A. notwithstanding B. for

　　

　　C. although D. as

　　

　　9. Vingo took a bus and headed for home, if his wife would have _____him back.

　　

　　A. not to know B. not known

　　

　　C. not knowing D. not having known

　　

　　10. We can make an exception _____.

　　

　　A. in any case of John B. in case of John

　　

　　C. in case of John's D. in the case of John

　　

　　11. When the Cultural Revolution was launched in China, his father _____college.

　　

　　A. attended B. had been attending

　　

　　C. was attending D. has been attending

　　

　　资料分析

　　

　　1. B。文章讨论的主要话题是不同的感冒病毒对人的影响，所以最合适的题目是“人和病毒”。

　　

　　2. D。文章并没有提到人们还没有找到任何治疗感冒的良方。

　　

　　3. B。文章第二段开头指出，B型病毒不稳定，而且往往会引起大范围的传染病的传播。

　　

　　4. A。通过文章的介绍，可以看出，A型病毒是这三种病毒中对人类危害的一种，因为它不稳定，并会造成危害性极大的流感的传播。

　　

　　5. B。assault的意思是“袭击”。

　　

　　6. D。文章最后一段说明，病毒传播的程度和它本身的强度，它遇到的抵抗力，和它传播的难易程度都是密切相关的。但是文章没有提到病毒能带来的免疫力。

　　

　　单项选择

　　

　　7. A。rational：有理性的。

　　

　　8. D。as：当……的时候。在这里是连词。

　　

　　9. C。not knowing.是分词短语作状语。表示动作发生的背景或者情况。

　　

　　10. D。in the case of.就……而言，对……来说。

　　

　　11. C。因为when引导的时间状语从句有较明确的“一点时间”，用过去进行时最好。