The-|||-CDC started a muln-state investgation i mid-August after receiving more than 150-|||-reports of senous respiratory distress (呼吸窘迫)among e-cigarette users,many of-|||-them teenagers and young adults. Within a couple of weeks,dozens more cases-|||-were reported, including the death of one e-cigarette user in Illinois.-|||-Ultimately, It turns out that the outbreak of lung disease is caused by the illegal use of-|||-drugs in e-cigarette devices But even so,such a finding would not mean that users-|||-of commercial nicotine (尼古丁)e-cigarettes can breathe easter. There are some-|||-pretty unpleasant things floating in that liquid nicotine that may be harmful to our-|||-health.-|||-For longtime smokers,the danger of lung cancer may well outweigh the dangers of-|||-smoking e-ogarettes.But there s always the risk of breathing chemicals, and if-|||-there`s any good to come out of this lung disease outbreak, pethaps it will be to bnng-|||-that lesson home to teenagers and young adults considenng taking up the e-cigarette-|||-habit-|||-14.Why do most people assume e-ongarettes safer than-|||-traditional ones?-|||-OA.Because traditional eigarettes us cheap-|||-materials.-|||-○B. Because e-cigarettes use heated liquid vapor.-|||-C.Because tradinonal cigarettes con more-|||-chemicals.-|||-○D. Because e-cigarettes use processed tobacco-|||-leaves.-|||-15.What was the unusual step that CDC took last week?-|||-OA.Startng an investigation into the outbreak of lung-|||-disease.-|||-B.Concluding an investigation among the 150 e--|||-cigarette users.-|||-C.Reporting the research results of serious-|||-respiratory distress.-|||-O Waming the public against using any e-clgarette-|||-devices.-|||-16.What caused the outbreak of lung disease among e--|||-cigarette users?-|||-OA.The commercial liquid nicotin-|||-B.The unpleasant things floalin In liquid chemicals.-|||-C.The frequent reuse of the same device.-|||-D.The illegal drugs in e-cagarette devices.-|||-17.Who are more likely to have the danger of lung cancer?-|||-OA.Adults using e-cigarettes.-|||-B.People with serious respiratory distress,