曰韩免费_91久久精品国产亚洲_一区二区成人影院_九一视频在线免费观看_91国视频_亚洲成人中文在线

四级冲刺练习阅读(191)

雕龙文库 分享 时间: 收藏本文

四级冲刺练习阅读(191)

  Dr. Jack M. Gwaltney, Jr. a professor at the University of Virginia School of Medicine, infected six student volunteers with virus , the most common cause of colds. A few days later, when they were coughing and sneezing, he gathered 37 more people and divided them into three groups. Group 1 members spent three days and nights in the same room with one of the infected students, separated by a screen so they couldnt touch one another. Group 2 sat around a table while an infected volunteer talked, coughed and sang to them. Group 3 held hands with an infected student for ten seconds, and then touched their own noses or eyes.

  Although most scientists at the time, the mid-70s, believed colds were spread by virus-laden droplets spread through the air when infected people coughed or sneezed, Gwaltney suspected physical contact might play an important role. Sure enough, of the 15 people who had touched a student volunteer, 11 became infected compared with only one of those who had been sitting at the table, and none who had spent three days and nights together.

  The best evidence we have is that hand-to-hand contact is the most efficient way of transmitting virus, says Gwaltney. The study was one of a series that helped establish Gwaltneys reputation as a leading authority.

  Dr. Robert Couch says, It would not be inappropriate to call him Mr. Common Cold.

  When Gwaltney is asked how close scientists are to finding a cure, he replies: If you mean eradication , I dont think were going to be able to do that with cold viruses any time soon. But if you look in the dictionary, youll see that cure is defined as a successful treatment. And were not just getting more effective at treating the symptoms were getting at the root cause too.

  21. Dr. Jack M. Gwaltney conducted the experiment in order to______.

  A. find out the most common cause of colds

  B. infect the student volunteer

  C. find out the role physical.contact plays in the common colds

  D. find out the role virus-laden air plays in the infection of colds

  22. The result of the experiment shows that ______ plays an important role in the

  infection of colds.

  A. sneezing at the infected person

  B. touching the infected person

  C. sitting together with the infected person

  D. talking with the infected person

  23. Which of the following statements is TRUE according to the passage?

  A. Dr. Gwaltney was sure that hand-to-hand touch is the cause of the common cold.

  B. Only one of the people who had spent three days and nights together became infected.

  C. Dr. Gwaltney conducted many an experiment as to the cause of colds.

  D. Dr. Gwaltney tested altogether 43 volunteers to see how they could develop colds.

  24. Mr. Common Cold is______.

  A. a newly-found virus

  B. a nickname of respect to Dr. Gwaltney

  C. a way by which the other scientists laughed at Dr. Gwaltney

  D. a method to cure colds

  25. When Dr. Gwaltney gives a reply in the end of the passage, he means that______.

  A. they have found the fundamental cause of colds

  B. they have managed to wipe out the cold viruses

  C. they have meant to experiment more

  D. they have made much progress in dealing with colds

  21. C 22. B 23. C 24. B 25. D

  

  Dr. Jack M. Gwaltney, Jr. a professor at the University of Virginia School of Medicine, infected six student volunteers with virus , the most common cause of colds. A few days later, when they were coughing and sneezing, he gathered 37 more people and divided them into three groups. Group 1 members spent three days and nights in the same room with one of the infected students, separated by a screen so they couldnt touch one another. Group 2 sat around a table while an infected volunteer talked, coughed and sang to them. Group 3 held hands with an infected student for ten seconds, and then touched their own noses or eyes.

  Although most scientists at the time, the mid-70s, believed colds were spread by virus-laden droplets spread through the air when infected people coughed or sneezed, Gwaltney suspected physical contact might play an important role. Sure enough, of the 15 people who had touched a student volunteer, 11 became infected compared with only one of those who had been sitting at the table, and none who had spent three days and nights together.

  The best evidence we have is that hand-to-hand contact is the most efficient way of transmitting virus, says Gwaltney. The study was one of a series that helped establish Gwaltneys reputation as a leading authority.

  Dr. Robert Couch says, It would not be inappropriate to call him Mr. Common Cold.

  When Gwaltney is asked how close scientists are to finding a cure, he replies: If you mean eradication , I dont think were going to be able to do that with cold viruses any time soon. But if you look in the dictionary, youll see that cure is defined as a successful treatment. And were not just getting more effective at treating the symptoms were getting at the root cause too.

  21. Dr. Jack M. Gwaltney conducted the experiment in order to______.

  A. find out the most common cause of colds

  B. infect the student volunteer

  C. find out the role physical.contact plays in the common colds

  D. find out the role virus-laden air plays in the infection of colds

  22. The result of the experiment shows that ______ plays an important role in the

  infection of colds.

  A. sneezing at the infected person

  B. touching the infected person

  C. sitting together with the infected person

  D. talking with the infected person

  23. Which of the following statements is TRUE according to the passage?

  A. Dr. Gwaltney was sure that hand-to-hand touch is the cause of the common cold.

  B. Only one of the people who had spent three days and nights together became infected.

  C. Dr. Gwaltney conducted many an experiment as to the cause of colds.

  D. Dr. Gwaltney tested altogether 43 volunteers to see how they could develop colds.

  24. Mr. Common Cold is______.

  A. a newly-found virus

  B. a nickname of respect to Dr. Gwaltney

  C. a way by which the other scientists laughed at Dr. Gwaltney

  D. a method to cure colds

  25. When Dr. Gwaltney gives a reply in the end of the passage, he means that______.

  A. they have found the fundamental cause of colds

  B. they have managed to wipe out the cold viruses

  C. they have meant to experiment more

  D. they have made much progress in dealing with colds

  21. C 22. B 23. C 24. B 25. D

  

主站蜘蛛池模板: 伊人色综合久久天天人手人婷 | 黃色一級片 | 国产人澡人澡澡澡人碰视频 | 精品国产高清a毛片 | 日本毛片在线观看 | h国产在线 | 精品国免费一区二区三区 | 日韩精品无码一区二区三区久久久 | 亚洲最大天堂无码精品区 | 久久精品国产亚洲7777小说 | 双乳被一左一右吃着动态图 | 18无码粉嫩小泬无套在线观看 | 女性女同性aⅴ免费观女性恋 | 国产精品久久久久久久免费大片 | 日韩手机在线视频 | 久久婷婷五月综合色奶水99啪 | 美国精品偷拍视频在线观看 | 强开小婷嫩苞又嫩又紧视频韩国 | 午夜成人亚洲理伦片在线观看 | 熟妇人妻无乱码中文字幕真矢织江 | 久久天天躁狠狠躁夜夜免费观看 | 久99re视频9在线观看 | 欧美成人区| 亚洲图片色 | 欧美精品在线一区二区三区 | 亚洲 欧洲 校园 自拍 都市 | 国产精品videossex白浆 | 国精产品一区二区三区有限公司 | 久久久久av综合网成人 | 青青草97国产精品免费观看 | 亚洲一区免费在线 | 精品无码国产一区二区三区av | 国产99视频精品免费视频7 | 激情偷乱人成视频在线观看 | 国产伦精品一区二区三区免费 | 久久久久一区二区三区 | 99国内精品久久久久久久 | 四虎永久免费地址在线观看 | 亚洲av片无码久久五月 | 日韩欧美亚洲一区精选 | 高清国产精品久久久久 |