2017年考研英语阅读理解考前冲刺试题第七套

来源：华课网校 [2016年12月8日] 【大中小】

　　第1页：2017年考研英语阅读理解考前冲刺试题第七套

　　第2页：考研各科目历年真题汇总（2016-2011）

　　第3页：2017年考研热点资讯推荐

　　第4页：2017考研英语模拟试题

　　第5页：2017考研英语备考辅导

　　Shortages of flu vaccine are nothing new in America， but this year's is a whopper. Until last week， it appeared that 100 million Americans would have access to flu shots this fall. Then British authorities， concerned about quality-control problems at a production plant in Liverpool， barred all further shipments by the Chiron Corp. Overnight， the U.S. vaccine supply dwindled by nearly half——and federal health officials found themselves making an unusual plea. Instead of beseeching us all to get vaccinated， they're now urging most healthy people between the ages of 2 and 64 not to. “This re-emphasizes the fragility of our vaccine supply，” says Dr. Martin Myers of the National Network for Immunization Information， “and the lack of redundancy in our system.”

　　Why is such a basic health service so easily knocked out? Mainly because private companies have had little incentive to pursue it. To create a single dose of flu vaccine， a manufacturer has to grow live virus in a 2-week-old fertilized chicken egg， then crack the egg， harvest the virus and extract the proteins used to provoke an immune response. Profit margins are narrow， demand is fickle and， because each year's flu virus is different， any leftover vaccine goes to waste. As a result， the United States now has only two major suppliers (Chiron and Aventis Pasteur)——and when one of them runs into trouble， there isn't much the other can do about it. “A vaccine maker can't just call up and order 40 million more fertilized eggs，” says Manon Cox， of Connecticut-based Protein Sciences Corp. “There's a whole industry that's scheduled to produce a certain number of eggs at a certain time.”

　　Sleeker technologies are now in the works， and experts are hoping that this year's fiasco will speed the pace of innovation. The main challenge is to shift production from eggs into cell cultures——a medium already used to make most other vaccines. Flu vaccines are harder than most to produce this way， but several biotech companies are now pursuing this strategy， and one culture-based product (Solvay Pharmaceuticals' Invivac) has been cleared for marketing in Europe.

　　For America， the immediate challenge is to make the most of a limited supply. The government estimates that 95 million people still qualify for shots under the voluntary restrictions announced last week. That's nearly twice the number of doses that clinics will have on hand， but only 60 million Americans seek out shots in a normal year. In fact， many experts are hoping the shortage will serve as an awareness campaign——encouraging the people who really need a flu shot to get one.

　　注(1)：本文选自Newsweek; 10/18/2004， p57-57， 2/3p， 1c;

　　注(2)：本文习题命题模仿对象1—4题模仿1997年真题text 3，第5题模仿1997年真题text 4的第四小题;

　　1. Shortages of flue vaccine show that ____.

　　[A] America relies too much on foreign suppliers

　　[B] the demand of flue vaccines is high this year

　　[C] quality problem is a serious problem in flu vaccine production

　　[D] the supply of flu vaccines is rather weak and America has no back-up measures to make it up

　　2. The word “cleared” (Line 5， Paragraph 3) might mean ____.

　　[A]permitted

　　[B]removed

　　[C]proved

　　[D]produced