10 cool things you should know about sharks?

1) sharks have very sensitive hearing, they can hear prey from 700ft away.
2) shark have very good smell, they can even smell the protein in blood from up to a mile away.
3) some shark lay eggs, others give birth to live young.
4) most shark babies are on their own after birth, if they get i mums way mums gonna eat them.
5) the shark species first appeared 400 million years ago, the main shark types around today evolved 100 million years ago.
6) for every human sharks kill over a million sharks are killed, more people are killed by deer than by sharks.
7) most fish scales are smooth, but sharks scales are actually teeth.
8) sharks have cartilage instead of bones, the only bones a shark has are teeth.
9) most fish have flaps over their gills, sharks don't.
10) most sharks must keep moving to live, as if they don't no oxygen passes through their gills and they will suffocate.