Do you like dolphins(海豚)? Dolphins live1water, but they are not fish. They are mammals (哺乳动物) that live in water. It has to(不得不) breathe(呼吸) air to the top of the water very often. A dolphin's nose isn't2to see. It's just a very small hole3top of the dolphin's head. This hole is called a blowhole. A dolphin4up every minute or so to breathe. It opens blowhole and takes air in, and then goes back into the water again. It can stay 5 the water for six or seven minutes if it has to. A dolphin's ears are very small,6its mouth is very7. It has almost one hundred teeth. A dolphin8very fast. Scientists are studying ways to 9boat go faster through the10.