Atpresent,itisgenerallybelievedthattobaccofirstoriginatedinAmerica.Archaeologicaldiscoveries,whenhumansstillinprimitivesociety,tobaccohasenteredintothelivesofAmerica.Tobaccosmokecontainsatleastthreechemicalsubstancesdangeroustohuman:tar,nicotineandcarbonmonoxide.Anicotinecontainedincigarettescankillamouse,20nicotineincigarettescankillacow.Man'sdeathis50~70mg,equivalentto20~25thenicotinecontentofcigarettes.First,theemotionalstateofsmokingcanbeadjusted.Second,thecrowd.Undertheinfluenceofcolleagues,partners,andmimictheirbehavior.Third,smokingsocialinteractionforsocializing.IV,smokingtoselftoshowoff.oralandthroatheartandarteriestheesophagusLungurinarybladderResultlungIsthispictureattractive?Howaboutthisone?ItcanresultincoughIfbabyswallowone,itlikelytodied.Itcaneffectivelyhookingtheirchild