Chum is a mixture of whale oil, a little whale meat, and lots of fish meat and blood. Most fishermen use chum to catch sharks. I learned lots about shark teeth. There are different kinds of shark teeth like ancient teeth from 380 million years ago. I learned lots about cartilage.
Cartilage is in the shark's body.
We have cartilage in our ear and nose. Instead of bones sharks have cartilage. I learned lots about the size of sharks. Some sharks are as long as 30 or 40 feet. Most sharks grow up to 9 or 10 feet long.