发布时间：2016-03-11 来源：环球网校 发布人：wyznl
Since 1939, numerous studies have been conducted to determine whether smoking is a health hazard. The trend of the evidence has been consistent and indicates that there is a serious health risk. Research teams have conducted studies that show beyond all reasonable doubt that tobacco smoking is associated with a shortened life expectancy.
Q: Smoking reduces one's life expectancy.