"Don't take it lightly," a doctor warns. "The concentration of some of the harmful substances contained in tobacco is higher in 'second-hand' smoke than in the 'mainstream' smoke inhaled by a smoker."
一位醫師警告：「香菸中所含的某些有害物質，在『二手菸』裡的濃度，比抽菸者直接吸入的『主流菸』還高。」