When you say shark almost every person are afraid of it especially kids because of the bad reputation they have especially in movies where they attack humans in the sea. This type of fish had been here more than the dinosaurs existed. Sharks live in the water all around the world in ocean and also in some lakes and rivers.
Compare to fish that are bony and has swim bladder, they do not have bones because cartilage is what made their skeletons. It is a fibrous, tough substance but not closely as hard as the bone and do not have swim bladder.
It is true that they are carnivores.
Do you not wonder is what is more a fact, if the sharks are treat or human are more the treat one? Sharks eats fishes, other sharks, squid, shellfish or other marine mammals. They do not usually attack human just to eat or bite unless they are threaten or harmed. Maybe if humans left them alone they will also left the human alone. But still being careful is more than important just to make sure..
Human can be a threat to them because some humans would capture sharks even it is still young just to cut the fins off and after they cut they throw the shark back in the sea. Shark finning is among the threat that sharks encounter to humans. And if this is not stop shark might also be listed under endangered species.
Each of that lives here on Earth has its purpose even the sharks has one. So don’t be afraid of them.