Hippos live in Africa. Their sweat is red. Sometimes they walk a long way to find water. In fact hippos walk in the water. They can't swim. Hippos love to play in the water in the day. They liked to eat plants at night. They never eat meat. They are easy to be angry. An adult hippo is about 3,000 kg. He can run very fast. But he cannot run a long way. His longest tooth is about 60 cm. His open mouth is big. A child can get into it. Crocodiles eat young hippos. But they cannot adult hippos. Two adult hippos are about    _    kg.
2,000 3,000 4,000 6,000