The hippopotamus河马，or hippo, lives

The hippopotamus河马，or hippo, lives in the hot part of Africa._____ (1) _____humans,dogs,and whales, it is a mammal哺乳动物.That is, its babies are alive, and they drink milk from the mother's body. The hippopotamus is a large grey animal with a big head and mouth. It _____ (2) _____four tons, or about 4,000 kilograms. Its stomach is seven meters long, and it eats only plants. It is a mammal, but it spends a lot of time in the water. During the day, it sleeps beside a river or a lake. Sometimes it wakes up. Then it goes under the water to get some _____ (3) _____ for food and never catches fish or hunts other animals. It can close its nose and stay under water for ten minutes. Its ears, eyes, and nose are high up on its head. It can stay with its body under the water and only its ears, eyes, and nose above the water. Then it can breathe the air. At night, the hippo walks on the nearby land and looks for food. It never goes very _____ (4) _____ the water. A baby hippo often stands on its mother's_____ (5) _____--the part of the body between the neck and legs. The mother looks for food underwater. The baby rides with a sure footing on her mother above the water.