answer:
we can't pollute water because there are creatures and organisims that live in the water so if we pollute it then they will die, besides you can filter the water to get rid of salt then you're able to drink the water and also use it for many other purposes.
The Uranium needed as fuel rare and must be processed.
The Myofilaments being used on a muscle contraction would return to their resting state when the sarcomeres would relax. The Sarcomeres are the individual contractile of the myofibrils which are then considered as the tiny rod like elements that are found within the muscle cells.
Convection occurs in water so I'll say its conduction