The blood brings oxygen to the body cells<span> and takes away their carbon dioxide. The blood that travels </span>back<span> to the </span>heart<span> and </span>lungs<span> is </span>dark red<span>. It has picked up carbon dioxide from the </span>body cells<span>, and it has left most of its oxygen with the cells.
I'm not 100% sure if this is the answer but it makes sense. The body is dependent on the drug to make it feel 'normal' So it would be physical dependence because obviously, the body is dependent on that drug. That's basically what withdrawals are.
