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【美文赏析】 Global Warming and the Polar Bear A Polar bears prefer to live in extremely cold artic climates. They live only in the Northern Hemisphere, on the arctic ice cap, and they spend most of their time on coastal areas. Polar bears are widely spread in Canada, extending from the northern arctic islands south to the Hudson Bay area. They are also found in Greenland, on islands off the shore of Norway, on the northern coast of the former Soviet Union, and on the northern and northwestern coasts of Alaska in the United States. B The polar bear is the largest members of the bear family. Males Polar Bears stand from eight to 11 feet tall and generally weigh from 500 to 1,000 pounds, but can weigh as much as 1,400 pounds. Female bears generally stand eight feet tall and weigh 400 to 600 pounds, except some, which can reach 700 pounds. The reason the polar bear weighs so much is that it stores about a four-inch layer of fat to keep it warm. The polar bear has a long, narrower head and nose, and small ears. It has coat that appears white but, each individual hair is actually clear and hollow. This helps the polar bear keep warm. The polar bear's coat helps it blend in with its snowy surroundings, this adaptation helps the Polar Bear hide while hunting. The polar bear's front legs are slightly pigeon-toed, and fur covers the bottoms of its paws. These adaptations help polar bears keep themselves from slipping on ice. C They mainly live on the meat but rarely eat plants. That is why it is considered to be a carnivore, or meat-eater. The ringed seal is the polar bear's primary prey. A polar bear hunts a seal by waiting quietly for it to emerge from an opening a seal makes in the ice, allowing them to breathe or climb out of the water to rest. Polar bears eat only the seal's skin and blubber of the seal. The remaining meat provides a food source for other animals in the Arctic. Polar bears also prey on young walrus’s. The remains of whale, seal, and walrus are also important sources of food for polar bears. In fact, because of their acute sense of smell, polar bears can sense animal remains from far away. (责任编辑：admin) |
