Since the other answer got deleted, i'll just answer it for you.
a sinoatrial node is the main pacemaker that begins each heartbeat located in the junctions of superior vena cava and the right atrium. It signals from the node that spread through the atria and determines the heart rates.
Answer:
Elements that are metals tend to lose electrons and become positively charged ions called cations. Elements that are nonmetals tend to gain electrons and become negatively charged ions called anions
Explanation:
It’s is letter B because in every other state they do not use uranium
