英语人教版保护环境北极熊的课文 北极熊通常在浮冰上抓捕海豹作为食物。但由于全球变暖，浮冰融化，在海上猎食也越来越困难，北极熊的捕猎场所也不得不转移到陆地上。 Polarbears usually subsist on seals, which they hunt from a platform of seaice. But the melting of sea ice as a result of rising globaltemperatures has made it more difficult for polar bears to hunt sealsat sea, confining the bears to land。 有更多的北极熊淹死在海里，因为它们被迫游向更远的海域去寻找食物。 Drowning is also more common as bears are forced to swim further out to sea to find food。 这些照片进一步证实了越来越多处于绝境之中的北极熊，为了生存，开始捕杀自己的同伴。科学家们称本年度内已经发生八起这样的事件。 Theimages add to the evidence that polar bears are increasingly hunting each other for food in their desperation to survive.Scientists say they are aware of eight cases so far this year。 美国地质调查局和世界自然保护联盟近日分析指出，在接下来的五十年内，由于全球变暖，极地浮冰融化，世界上仅存的20000到25000只北极熊还将减少三分之二。 Recentanalysis by the US Geological Survey and World Conservation Union found that two-thirds of the 20,000 to 25,000 polar bears in the world couldbe lost in the next 50 years as warming temperatures melt the ice。 失去浮冰栖息地，北极熊将无法长期生存下去。其他威胁，包括原油和天然气钻探、海运及有毒物质污染，与气候剧变和浮冰融化相比都不值一提。 Without the sea ice habitat, the polar bear will not survive in the long term.There are other threats, such as oil and gas drilling, shipping and toxins, but they pale in comparison to climate change and the loss of the sea ice。 本文来源：https://www.wddqw.com/doc/1dc1bb64306c1eb91a37f111f18583d049640f89.html