Today ,as in every other day of the year ,more than 3000 U.S. adlescents will smoke their first cigarette on their way to becoming regular smokers as adults. During their lifetime,it can be expected that of these 3000 about 23 will be murdered,30 will die in traffic accidents, and nearly 750 will be killed by a smoking-related disease. The number of deaths attributed to cigarette smoking outweithts all other factors, whether voluntary or involuntary, as a cause of death. Since the late 1970s, when daily smoking among high school seniors reached 30 precent , smoking rates among youth have declined . While the decline is impressive ,several important issues must be raised. First, in the past several years,smoking rates among youth have declined very little. Second,in the late 1970s ,smoking among male high school seniors exceeded that among female by nearly 10 percent . The statistic is reversing.Third ,several recent studies have indicate high school dropouts have excessively high smoking rates, as much as 75 percent . Finally, thouth significant declines in adolescent smoking have occurred in the past decade,no definite reasons for the decline exist. Within this context,the Naional Cancer Instiute (NCI) began its current effort to determine the most effecive measures to reduce smoking levesl among youth. What is implied but not stated by the author is that ().
A. smoking rates among youth have declined very little
B. there are now more female than male smokers among high school seniors
C. high smoking rates are due to the incease in wealth
D. smoking at high school are from low socio-economic background
2006年至2011年全年我国农村居民人均纯收入分别为3587元、4140元、4761元、5153元、5919元、6977元;城镇居民人均可支配收入分别为11759元、13786元、15781元、17175元、19109元、21810元。2000年至2011年全年我国粮食产量分别为49804万吨、50160万吨、52871万吨、53082万吨、54648万吨、57121万吨。与2010年相比,2011年全年粮食种植面积11057万公顷,增加70万公顷;棉花种植面积304万公顷,增加19万公顷,油料种植面积1379万公顷,减少10万公顷;糖料种植面积195万公顷,增加4万公顷;棉花产量660万吨,增产10.7%;油料产量3279万吨,增产1.5%;糖料产量12820万吨,增产43%;肉类总产量7957万吨,增长0.4%,其中,猪肉产量5053万吨,下降0.4%;养殖水产品产量4026万吨,增长5.2%;捕捞水产品产量1574万吨,增长19%。2011年末全国参加城镇基本医疗保险的人数47291万人,增加4028万人。其中,参加城镇职工基本医疗保险人数25226万人,参加城镇居民基本医疗保险22065万人。截至9月底,2646个县(市、区)开展了新型农村合作医疗工作,新型农村合作医疗参合率97.5%;新型农村合作医疗基金支出总额为1114亿元,受益84亿人次。2011年我国城镇居民人均可支配收入比2008年大约增加了()
A. 18%
B. 38%
C. 58%
D. 85%