四级复习资料大全阅读(18)

　　The process of vaccination allows the patients body to develop immunity to the virus or disease so that, if it is encountered, one can ward it off naturally. To accomplish this, a small weak or dead strain of the disease is actually injected into the patient in a controlled environment, so that his bodys immune system can learn to fight the invader properly. Information on how to penetrate the diseases defenses is transmitted to all elements of the patients immune system in a process that occurs naturally, in which genetic information is passed from cell to cell. This makes sure that, should the patient later come into contact with the real problem, his body is well equipped and trained to deal with it, having already done so before.

　　There are dangers inherent in the process, however. On occasion, even the weakened version of the disease contained in the vaccine proves too much for the body to handle, resulting in the immune system succumbing, and, therefore, the patients death. Such is the case of the smallpox vaccine, designed to eradicate the smallpox epidemic that nearly wiped out the entire Native American population and killed massive numbers of settlers. Approximately 1 in 10,000 people who receives the vaccine contract the smallpox disease from the vaccine itself and dies from it. Thus, if the entire population of the United States were to receive the Smallpox Vaccine today, 3000 Americans would be left dead.

　　Fortunately, the smallpox virus was considered eradicated in the early 1970s, ending the mandatory vaccination of all babies in America. In the event of a re-introduction of the disease, however, mandatory vaccinations may resume, resulting in more unexpected deaths from vaccination. The process, which is truly a mixed blessing, may indeed hide some hidden curses.

　　36.The best title for the text may be_______

　　[A] Vaccinations: A Blessing or A Curse.

　　[B] Principles of Vaccinations.

　　[C] Vaccines: Methods and Implications.

　　[D] A Miracle Cure Under Attack.

　　37.What does the example of the Smallpox Vaccine illustrate?

　　[A] The possible negative outcome of administering vaccines.

　　[B] The practical use of a vaccine to control an epidemic disease.

　　[C] The effectiveness of vaccines in eradicating certain disease.

　　[D] The method by which vaccines are employed against the disease.

　　38.The phrase ward it off naturally most probably means_______

　　[A] dispose of it naturally.

　　[B] fight it off with ease.

　　[C] see to it reluctantly.

　　[D] split it up properly.

　　39.Which of the following is true according to the text?

　　[A] Saving the majority would necessarily justify the death of the minority.

　　[B] The immune system can be trained to fight weaker versions of a disease.

　　[C] Mandatory vaccinations are indispensable to the survival of the populace.

　　[D] The process of vaccination remains a mystery to be further resolved.

　　40.The purpose of the author in writing this passage is_______

　　[A] to comment and criticize.

　　[B] to demonstrate and argue.

　　[C] to interest and entertain.

　　[D] to explain and inform.