Smoking can affect the lungs and give you lung cancer. When someone smokes, they would inhale the smoke, causing the smoke from the cigarettes to go into your lungs.
Alcohol is bad because 1. you have constant mood swings. They don't fully realize what is going on and their mood changes a lot; sometimes hurting the ones that love them. 2. It is a very expensive habit. Because of this habit some people have gone violent towards the people they love. And 3. some people because of the excess can die because their liver has too much alcohol and it is way too much for your liver to work with which means you either get a transplant- which is hard- or you die. There is a bigger chance of death which means you'll be leaving your loved ones alone and hurt.
I think that it is a but im not sure of that so dont be dependant on my anwser