In the vast ocean live many creatures with great intellectual and physical capacities. Dolphin is one of those great creatures, whose capacities to think and move at an astounding rate puzzle those who study their behaviors, Dolphins possess something that makes them different from all the other sea creatures. It is not strength or speed but the size of their brains. Dolphin's brain is almost the same size as that found in the human head. They live for a ling time.

　　Dolphins'babies are born in the water. They can grow up to three and a half meters long.

　　Dolopins use sound to help them find their way, look for their food and talk with each other. Sound is just like their eyes and mouths.