14．（8分）Most viruses can be found and killed by our immune system as soon as they enter our bodies.However，some viruses，for example，the coronavirus，are sneaky.They are difficult to recognize and find.These viruses can cause deadly diseases，like COVID﹣19.Human﹣to﹣human transmission can easily occur，and pandemic will therefore break out.Vaccination is by now a simple，safe and effective way to protect us from the diseases.
▲Vaccines are something that "looks" exactly the same as the viruses，mainly made from the viruses that are weakened or killed.They will not make us really ill.They only stimulate and activate our immune system to work，telling it something harmful is coming in.The immune system will know what the "viruses" look like，and send B cells（lymphocytes）or antibodies to find and kill them.Meanwhile，B cells will remember them for the next kill.A vaccine may also give us passive immunity by providing B cells taken from an animal or a human to play the same role.
Scientists have developed more than 180 vaccines to fight against COVID49.The technical approaches of these vaccines can be a little different，but their aims are the same.
Take the inactivated vaccine as an example.In an inactivated vaccine，the coronaviruses are already killed or made into the ones unable to produce more new viruses.When the immune system "sees" them，it will try to kill them.The question is：without enough these viruses• how can B cells remember them？That's why we need to take the vaccine more than one time.Though this vaccine is safe，it might not be as effective as it is expected to be.
The live﹣attenuated vaccine is different.In this vaccine，the viruses are weakened，but they are alive.They can produce enough new viruses to train the immune system to kill and remember them，so people only need to take the vaccine once.The live﹣attenuated vaccine is considered the most effective，but there is a worry：what might happen once these viruses wake up？
Therefore，although vaccination is by now one of the best ways to protect us from COVID﹣19，it can be better.

（1）The coronavirus can  　C　.
A.not be killed
B.not be found
C.cause deaths
D.stop pandemic
（2）Which of the following can be the best topic sentence of Paragraph 2？ 　C　
A.Vaccination can provide us with B cells.
B.Vaccines are made from different viruses.
C.Vaccination can prepare us against viruses.
D.Vaccines won't make us ill as the viruses do.
（3）Compared to the inactivated vaccine，the live﹣attenuated vaccine  　D　.
A.needs taking more than once
B.is equally safe
C.contains viruses that are killed
D.is more effective
（4）What can we learn from the passage？ 　 　
A.Vaccination is good enough to treat COVID﹣19.
B.The immune system can be more effective with vaccines.
C.The viruses in inactivated vaccines can make new viruses.
D.180 vaccines have been developed to fight against diseases.

【分析】本文主要介绍了疫苗是帮助身体免受病毒侵害最好的方法之一。
【解答】（1）C.细节理解题。根据第一段However，some viruses，for example，the coronavirus，are sneaky.They are difficult to recognize and find.These viruses can cause deadly diseases，like COVID﹣19.然而，一些病毒，例如冠状病毒，是偷偷摸摸的。他们很难识别和发现。这些病毒可以导致致命的疾病，如COVID﹣19。可知冠状病毒能造成死亡。故选C。
（2）C.推理判断题。根据第二段段意，疫苗是一种"看起来"与病毒完全相同的东西，主要由被削弱或被杀死的病毒制成。它们不会让我们真正生病。它们只是刺激和激活我们的免疫系统，告诉它有害的东西来了。免疫系统将知道这些"病毒"的样子，并发送B细胞(淋巴细胞)或抗体去发现并杀死它们。与此同时，B细胞会记住它们以备下一次杀戮。疫苗也可以通过提供从动物或人身上提取的B细胞来起到同样的作用，从而使我们产生被动免疫。可知，本段主要介绍了接种疫苗可以使我们防备病毒。故选C。
（3）D.细节理解题。根据倒数第二段The live﹣attenuated vaccine is considered the most effective，but there is a worry：what might happen once these viruses wake up？减毒活疫苗被认为是最有效的，但令人担忧的是:一旦这些病毒苏醒，可能会发生什么？可知，与灭活疫苗相比，减毒活疫苗更加有效。故选D。
（4）B.推理判断题。通读全文可知，本文主要介绍了疫苗是帮助身体免受病毒侵害最好的方法之一。因此免疫系统接种疫苗会更有效。故选B。
【点评】通读全文，理解文章大意，阅读题目后返回原文阅读并找出与题目相对应的内容，仔细核对，选择符合原文原意的答案，完成后再次阅读并检查。