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第二节：完形填空（共20小题，每小题1.5分，满分30分）
阅读下面短文，从短文后各题所给的四个选项（A、B、C、D）中，选出可以填入空白处的最佳选项。
Parents who smoke often open a window or turn on a fan to clear the air for their children, but experts now have identified a related threat to children's health that isn't as easy to get rid of: third-hand smoke。
　　That's the term being 21    to describe the invisible yet poisonous mixture of gases and particles(颗粒) clinging （依附）to smokers' hair and 22    , not to mention cushions and carpeting, that stays long after second-hand smoke has cleared from a room. The remaining  23   heavy metals, carcinogens(致癌物) and even radioactive materials that young children can get on their hands and take  in, 24  if they're crawling or playing on the floor。
　　Doctors from MassGeneral Hospital for Children in Boston coined the term "third-hand smoke" to 25 these chemicals in a new study that 26    on the risks they pose to infants and children. The study was published in the  27    issue of the journal Pediatrics。
　　"Everyone knows that second-hand smoke is bad, 28   they don't know about this," said Dr. Jonathan P. Winickoff, the lead author of the study and an assistant professor of pediatrics at Harvard Medical School。
　　"When their kids are 29  the house, they might smoke. Or they smoke in the car. Or they strap(用带子捆扎) the kid in the car seat in the back and crack the window and 30   , and they think it's okay because the second-hand smoke isn't getting to their 31   . We needed a term to describe these tobacco toxins that aren't 32   ."
　　The study reported on 33   toward smoking in 1,500 households across the United States. It found that the vast majority of both smokers and nonsmokers were 34   that second-hand smoke is harmful to children. Some 95 percent of nonsmokers and 84 percent of smokers 35  with the statement that "inhaling smoke from a parent's cigarette can 36    the health of infants and children"。
　　But 37   fewer of those surveyed were aware of the  38   of third-hand smoke. Since the term is so new, the researchers asked people if they agreed with the statement that "breathing air in a room 39  where people smoked yesterday can harm the health of infants and children"。
　　Only 65 percent of nonsmokers and 43 percent of smokers agreed with that 40   , which researchers interpreted as acknowledgement of the risks of third-hand smoke.
21.A  told      B discussed     C  used       D  mentioned
22. A shoes      B clothing     C  body        D  mouth
23. A includes    B covers      C finds          D  improves
24. A especially   B specially    C immediately  D  regularly
25. A name       B call        C explain        D  describe
26. A focused     B  tended    C tried           D  worked
27. A later       B latest        C best           D  previous
28. A but        B and         C however        D   or 
29. A alongside   B out of       C in              D  beside
30. A cough     B  talk        C observe         D smoke 
31. A cars       B seats         C kids           D  windows
32. A visible    B  invisible     C poisonous       D concrete
33. A  policies  B  attitudes      C bans            D habits
34. A  told     B content       C  confident       D  aware
35. A opposed   B agreed        C fought          D  connected
36. A harm      B destroy       C improve         D confuse
37. A quite      B very        C far              D  too
38. A chances   B risks          C abilities          D conditions
39. A tomorrow   B today        C yesterday         D  weekend
40. A statement   B mark         C discussion        D prejudice