江西省2017届高三英语二轮专项训练:阅读表达+写作(29) 第一节 阅读表达阅读下面短文,并按照题目要求用英语回答问题〔1〕Secondhand smoke is a byproduct of cigarette, cigar or pipe smoking.Secondhand smoke occurs when tobacco burns or when smokers exhale, and it is inhaled involuntarily by non-smokers. 〔〕Secondhand smoke___________________.The first is called side stream smoke, which is the smoke released from the burning end of a cigarette or cigar, or from tobacco burning in the bowl of a pipe.The second is called mainstream smoke, which is exhaled by a smoker. 〔〕When nonsmokers are exposed to secondhand smoke, they inhale many of the same cancer-causing chemicals that smokers inhale.According to the U.S.Surgeon General, cigarette smoke contains more than 4,000 chemical compounds, including more than 50 cancer-causing chemicals, and at least 250 chemicals that are either toxic or carcinogenic. 〔4〕Both side stream and mainstream smoke are dangerous to nonsmokers.Side stream smoke is generated at lower temperatures and under different conditions than mainstream smoke.As a result, it contains higher concentrations of many of the toxins found in cigarette smoke. 〔〕Secondhand smoke has been designated as a known human carcinogen by the U.S.Environmental Protection Agency, the National Toxicology Program, and the International Agency for Research on Cancer.Secondhand smoke also is listed as an occupational carcinogen by the National Institute for Occupational Safety and Health. |