题目内容：

 

    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 1to describe the invisible yet poisonous mixture of gases and particles(颗粒) clinging （依附）to smokers' hair and 2, not to mention cushions and carpeting, that stays long after second-hand smoke has cleared from a room. The remaining  3heavy metals, carcinogens(致癌物) and even radioactive materials that young children can get on their hands and take  in, 4if they're crawling or playing on the floor。

　　Doctors from MassGeneral Hospital for Children in Boston coined the term "third-hand smoke" to 5these chemicals in a new study that 6on the risks they pose to infants and children. The study was published in the  7issue of the journal Pediatrics。

　　"Everyone knows that second-hand smoke is bad, 8they 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 9the 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 10, and they think it's okay because the second-hand smoke isn't getting to their 11. We needed a term to describe these tobacco toxins that aren't 12."

　　The study reported on 13toward smoking in 1,500 households across the United States. It found that the vast majority of both smokers and nonsmokers were 14that second-hand smoke is harmful to children. Some 95 percent of nonsmokers and 84 percent of smokers 15with the statement that "inhaling smoke from a parent's cigarette can 16the health of infants and children"。

　　But 17fewer of those surveyed were aware of the  18of 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 19where people smoked yesterday can harm the health of infants and children"。

　　Only 65 percent of nonsmokers and 43 percent of smokers agreed with that 20, which researchers interpreted as acknowledgement of the risks of third-hand smoke.

1.A  told      B discussed     C  used       D  mentioned

2.A shoes      B clothing     C  body        D  mouth

3.A includes    B covers      C finds          D  improves

4.A especially   B specially    C immediately  D  regularly

5.A name       B call        C explain        D  describe

6.A focused     B  tended    C tried           D  worked

7.A later       B latest        C best           D  previous

8.A but        B and         C however        D   or 

9.A alongside   B out of       C in              D  beside

10.A cough     B  talk        C observe         D smoke 

11.A cars       B seats         C kids           D  windows

12.A visible    B  invisible     C poisonous       D concrete

13.A  policies  B  attitudes      C bans            D habits

14.A  told     B content       C  confident       D  aware

15.A opposed   B agreed        C fought          D  connected

16.A harm      B destroy       C improve         D confuse

17.A quite      B very         C far              D  too

18.A chances   B risks          C abilities          D conditions

19.A tomorrow   B today        C yesterday         D  weekend

20.A statement   B mark         C discussion        D prejudice