No they don’t. There are many reasons for this, including the ability of each person to skate. At skating sessions that are open to the public there are rules designed to make it safer for everyone. The middle of the rink is usually used for beginners and for figure skaters working on slow or almost stationary skills, such as spins. Skaters are all required to move in the same direction. Often skating backwards is only allowed if the person is skating with someone holding them who is skating forward. Sticks and pucks are usually banned as is jumping. There is usually a monitor whose job is to stop people from doing things that are dangerous, especially if they are making it dangerous for others.
Plasma is the liquid component of blood, in which the red blood cells, white blood cells, and platelets are suspended. It constitutes more than half of the blood's volume and consists mostly of water that contains dissolved salts (electrolytes) and proteins.
