阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。
A
COVID-19 vaccinations (接种) are underway. Anthony Fauci, director of the National Institute of Allergy and Infectious Disease, has said that about 75% to 90% of Americans will need to be vaccinated to reach herd immunity (群体免疫) in the United States. Public health experts recommended a staged approach to vaccination. Demand for the vaccine exceeded capacity in the beginning. Vaccine manufacturers increased production to meet the demand; however, public interest in getting vaccinated has been waning. The U.S. adopted the following staged approach, but by May 1,2021, most of the country had already reached stage 2.
Stage la includes healthcare personnel and residents of nursing homes and assisted living facilities. Stage la vaccinations began in December 2020. Stage 1b includes frontline essential workers: police officers; food and agricultural, postal, daycare, grocery store, public transit, and manufacturing workers; teachers; and people aged 75 and older. Some states are allowing people aged 65 and older to sign up for the vaccine. S me states began Stage 1b vaccinations during the second full week of January 2021.
Stage 1c includes people aged 65.to 74 and people aged 16 to 64 who have potential health conditions that increase the risk of COVID complications. Essential workers of any age in the transportation, logistics, food service, construction, communications, information technology, energy, law, media, public safety, and public health sectors are also in Stage lc. Many states were able to vaccinate Stage lc in March and April.
Stage 2 includes all other people aged 16 and older. A COVID-19 vaccine is now authorized for teens aged 12 and older.
For more information about vaccine injection, you may contact 415-578-7342.
21. What does the underlined word “waning” in paragraph 1 mean?
A. Increasing. B. Decreasing. C. Changing. D. Improving.
22. Which of the following statements is true according to the passage?
A. Many states of the U.S. are able to reach stage lc before January, 2021.
B. The U. S. plans to vaccinate all people aged 12 and older at the end of the two stages.
C. To reach herd immunity, more than 90% of Americans will need to be vaccinated.
D. In stage 1b a man aged 66 can get vaccinated in some states of America.
23. Where is the text probably taken?
A. An announcement. B. A biology textbook.
C. A news report. D. A medical journal.
【答案】21. B22. D23. A
【解析】
【分析】本文是一篇应用文，主要讲的是美国分阶段接种新冠疫苗的相关信息。
【21题详解】
词句猜测题。根据第一段的“Vaccine manufacturers increased production to meet the demand(疫苗制造商增加生产以满足需求)”及后面的however表转折可知，疫苗制造商增加生产以满足需求；然而，公众对接种疫苗的兴趣正在减弱。由此推知，划线词waning的意思是 “减少”，即Decreasing。故选B。
【22题详解】
细节理解题。根据第二段的“Stage 1b includes frontline essential workers: police officers; food and agricultural, postal, daycare, grocery store, public transit, and manufacturing workers; teachers; and people aged 75 and older. Some states are allowing people aged 65 and older to sign up for the vaccine.(第1b阶段包括前线的重要工作人员：警务人员；食品和农业、邮政、日托、杂货店、公共交通和制造业工人；教师；以及75岁以上的人。一些州允许65岁及以上的人注册接种疫苗)”可知，在1b阶段，在美国的一些州，66岁的男子可以接种疫苗。故选D。
【23题详解】
推理判断题。根据最后一段的“For more information about vaccine injection, you may contact 415-578-7342.(有关疫苗注射的更多信息，请联系415-578-7342)”可知，主要讲的是美国分阶段接种新冠疫苗的相关信息。由此推知，本文来自于一份公告。故选A。
