Fast twitch fibers are best suited for a long term, so it true.
I'm pretty sure it's to boost dental health. fluoride is used to prevent cavities and tooth decay, so i'm assuming its option 3.
I think they put flavoring in the liquid cartridges to make them more addictive. People are going to want the newer flavors because of the taste. Some people use them as coping skills or sometimes to be “trendy” or “cool”. E-cigarettes are very damaging to your lungs worse then regular cigarettes.
The answer is true because, they are trying to better themselves and they are trying to break the addiction by doing something that is healthy rather than doing something that will harm them.