大学英语试题3答案!quiz3Polio (小儿麻痹症) was one of the most feared dise

大学英语试题3答案!quiz3
Polio (小儿麻痹症) was one of the most feared diseases of the first half of the 20th century.It appeared 21.by chance by turns by mistake ,mostly in children,causing parents to worry during the epidemics of the 1940s and 1950s.President Franklin Delano Roosevelt caught the disease in 1921.He was 22.remained left got without the use of his legs.
Different to what is commonly believed,polio did not typically 23.result in emerge in happen in serious damage to one's legs.24.Rather than In place of Rather ,the majority of individuals who caught it only 25.implemented experienced experimented small problems,such as fever and headache.These difficulties only 26.went passed lasted a few days,and many had such small cases 27.that which so they did not even realize they were ill.28.Therefore However In such ,they often continued 29.during while with their daily lives,attending school or work,unknowingly giving many others the virus.This explains 30.when why how many people who had serious cases of polio believed that they were the only one in their family,neighborhood,or community to have 31.had done suffered the disease.In truth,there could have been many individuals 32.for to with whom they came into contact that had the illness,33.since so but did not show symptoms.
In 1948,Jonas Salk 34.made started worked research on a vaccine for the disease.35.After all Than Then in 1955,the Salk vaccine was shown to be 36.operative efficiency effective in preventing the disease after trials 37.involving affecting protecting nearly two million children.A nationwide program to vaccinate (接种疫苗) was quickly started and 38.since after before several years and improvements on the vaccine by Albert Sabin,the United States was almost entirely 39.rid of done away put an end to the disease.Today,polio is all but forgotten,as it has 40.completely relatively inevitably disappeared