【文章內(nèi)容簡介】 ions(并發(fā)癥) caused by bacteria.Accurate prediction is difficult because of the plication 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.15. Which of the following is the most appropriate title for the passage?A. Symptoms of InfluenzaB. Man Versus VirusC. World Health Organization: Forefront against Influenza VirusD. Variability of Influenza Virus16. 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.17. 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.18. Which of the following is the most dangerous virus according to the passage?A. influenza A virus B. influenza B virusC. influenza C virus D. it cannot be determined by the information provided19. What does the word “assault” in the eighth line of the last paragraph mean?A. influence B. attack C. symptom D. damage20. Which of the following is NOT mentioned as a factor contributing to the extent to which a virus spreads?A. the strength of the virusB. the strength of the opposition the virus encountersC. the ease with which the virus can be transmittedD. the immunity the virus can inducePart II Vocabulary and Structure Directions: There are 30 inplete sentences in this part. For each sentence there are four choices marked A., B., C. and D. Choose the ONE that best pletes the sentence. Then mark the corresponding letter on the Answer Sheet with a single line through the center.21. The facts he supplied were not relevant _____the case in question.A. with B. to C. for D. about22. A mittee has been _____ by the counsel to look into the causes of unemployment.A. designed B. devised C. worked D. set up23. Few articles in the newspapers _____more attention than that reporting the murder case with . Simpson involved.A. enlist B. divert C. draw D. absorb24. Julia _____two children since she got married in 1990.A. gives birth to B. has given birth toC. has been giving birth to D. gave birth to25. The hospital was built on the side of a river, hence _____.A. it has the name Riverside B. given the name RiversideC. has got the name Riverside D. the name Riverside26. It took them several weeks to _____the wild horse.A. cultivate B. civilize C. curb D. tame27. By the time you graduate, we _____in Australia for one year.A. will be staying B. will have stayedC. would have stayed D. have stayed28. He appreciated _____the chance to deliver his thesis in the annual symposium on Comparative Literature.A. having given B. to have been givenC. to have given D. having been given29. They left for the airport very early in the morning _____traffic jam.A. in line with B. at the risk ofC. in case of D. for the sake of30. Living in the desert involves a lot of problems, _____water shortage is the worst.A. not to mention B. of whichC. let alone D. for what 31. The government official can hardly find sufficient grounds _____his arguments in favor of the revision of the tax law.A. on which to base B. which to be based onC. to base on which D. on which to be based32. Hydrogen is one of the most important element in the universe _____it provides the building blocks from which the other elements are produced.A. so that B. but thatC. provided that D. in that33. Just as relaxation is an important part of our lives, _____ stress.A. so is B. as it isC. and so is D. the same is34. While a young man, he decided to put aside a little money every month to make for his old age.A. provision B. supply C. adjustment D. insurance35. The sales department has submitted a _____of their annual sales report to the board of directors.A. schedule B. sketch C. shorthand D. scheme36. 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. credible37. The final exams approached, _____the students became mo