Polar bears monstly live on the sea ice. They are good at swimming. Polar bears weigh only seberal grams at birth. But they may weigh as much 900 kilograms when they grow up. Thay can live for 25 years. They eat the animal in the sea. However, polar bears are in danger now. Why? First, it's because the earth is becoming warmer and warmer. There is less and less ice, polar bears are losing their homes. Second, people are killing them for their fur and meat. The fur of polar bears is thick enough for people to keep warm in winter.

It's important for people to protect polar bears.We mustn't kill the polar bears. They are our friends. We should proyect the enviorment.