1. Camels help people to travel. They are very comfortable becase they dont need water for a long time.
2. Cows give milk for people. Then we can do cheeze, for example.
3. I dont know, sorry
4. People were eating whales, now some of them are in red book
5. People always make leather products from crocodiles
6. People use sheep's wool to make a lot of things. Hats, socks...