Polar bears live in such environment that is too cold for most animals. For much of the year, they live and hunt on the (freeze) Arctic sea ice. Nature has prepared them for the cold conditions but nothing has prepared them for the danger threatens their only home.
Polar bears' world is melting. Polar bears (suffer) in a warmer world are in danger. Studies show that the polar ice (reduce) by 9.8% every ten years since 1978. At present, about 20,000 to 25,000 polar bears live in the Arctic. Polar bears depend on the sea ice for their (survive)."The sea ice is more than just the platform that the bears walk ." says Andrew Derocker, who studies North American polar bear population. "Without it, they can't exist."
Some melting and refreezing of the polar ice is nature. But in warmer world, these cycles speed up, and bears have (little) to hunt. (normal), they have three months in the spring when they gain more weight and the extra fat (use) later, when the bears are not actively hunting. Therefore, it's urgent to protect the environment and maintain the ecological balance.
