Questions about Smoking

Hello! This is LME!
        We have some questions that we hope to have answered. The questions we hope to have answered are:

1.    Why do people get addicted to smoking? 
2.    What causes adolescence to get involved with smoking?
3.     What makes it so hard to quit smoking?
4.    What are the affects on people who inhale the smoke released from a cigarette?
5.     What are the affects on the user of the cigarette?