Most smokers want to stop smoke. Many of 76. ______ them have tried more than once but failed. 77.______ Although they know smoking may kill them and 78.______ cause a serious illness yet they can give it up. 79.______ The reason to it is that tobacco contains nicotine 80.______ that is a drug which gets one into habit of smoking. 81.______ Because you start taking the drug, it is hard to stop. 82.______ If you go without it for an hour or two, it 83.______ begin to feel bad. The only thing can stop 84.______ you feeling bad is the drug containing in cigarettes. 85.______