寒冷环境中的动物适应

了解极地动物如何在极端寒冷中生存——海豹和鲸鱼靠厚厚的脂肪层（鲸脂）隔热保暖，北极熊中空的毛发可以锁住空气来保持体温，企鹅的鳍状肢通过逆流热交换防止热量散失，北极狐长出厚厚的白色冬毛既保暖又便于伪装，还有一些动物会迁徙以避开最寒冷的季节。

Understand how polar animals are adapted to survive extreme cold — blubber (thick fat layer) insulates seals and whales, hollow fur traps air for warmth in polar bears, counter-current heat exchange in penguin flippers prevents heat loss, Arctic foxes grow thick white winter coats for camouflage and warmth, and some animals migrate to avoid the harshest months

学习证据 / Evidence

• 描述至少三种寒冷环境中的适应特征：鲸脂、中空毛发、逆流热交换、白色冬毛或迁徙。
• 解释每种适应特征的作用（例如，鲸脂能隔绝冷水，白色毛发在雪中起到伪装作用）。
• 正确使用“适应”一词，表示帮助动物在特定环境中生存的特征。

• Describe at least three cold-weather adaptations: blubber, hollow fur, counter-current heat exchange, white winter coats, or migration
• Explain the purpose of each adaptation (e.g. blubber insulates against cold water, white fur provides camouflage in snow)
• Use the word adaptation correctly to mean a feature that helps an animal survive in its environment

评估问题 / Assessment

{{name}}能说出几种极地动物在严寒中生存的方法吗？比如北极熊中空的毛发锁住温暖空气、海豹厚厚的鲸脂，或者北极狐在冬天变色？

Can {{name}} explain several ways polar animals survive the freezing cold — like a polar bear's hollow fur trapping warm air, a seal's thick blubber, or an Arctic fox changing colour in winter?