polar bear

例句：

1. 1. Polar bears are known for their unique black and white fur.
   北极熊以其独特的黑白毛皮而闻名。
2. 2.The polar bear is one of the most endangered species in the world.
   北极熊是世界上最濒危的物种之一。
3. 3. Polar bears spend most of their lives hunting for seals and other marine mammals.
   北极熊大部分时间都在狩猎海豹和其他海洋哺乳动物。