亲子 备孕 怀孕 新生儿 0-1岁 1-3岁 3-6岁
polar bear,n.北极熊; 白熊;[例句]The polar bear's white fur is a natural camouflage.北极熊的白色毛皮是天然的保护色。[其他] 复数:polar bears.