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2025-07-21 03:19 本頁(yè)面
【正文】 polar bears is so close that the abundance of ringed seals in some areas appears to regulate（調(diào)節(jié)） the density（密度） of polar bears, while polar bear predation in turn regulates density and reproductive success of ringed seals. ? The evolutionary pressure of polar bear predation on seals probably accounts for some significant differences between Arctic and Antarctic seals. Because polar bears play an important role in Arctic environment, scientists feel that polar bear can be a good indicator of the health of Arctic environment. So, we can say that by protecting polar bears, we are protecting the whole Arctic ecosystem. Global warming has an impact on the ice. The ice is melting quickly in north and south pole. And that have a bad influence on polar bears. Due to the global warming, Arctic ice began to melt, the polar bear’s home
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