英语听力：自然百科 冰冻星球 前往地球尽头(10)（在线收听）

As the warm humid air from the south meet the cold Arctic, the moisture is crystalized and snowflakes form from the sky. Each crystal froms around a particle of dust. All have a six-fold symmetry, but no two have ever been found with exactly the same shape. Their variety and complexity is breathtaking.Each snowflake is water waiting to be released in spring. For this reason, snow is the lifeblood of these silent forests and all that live here depend on it in one way or another. Some, like the great grey owl, appear in spring for the booming times then vanish like phantoms. Others, like their lemming prey, are here year around beneath the snow, insulated from the cold air above.The northern forests are across road for seasonal visitors and Arctic specialists. But they are so much more than this. Together they make up the tiger an unbreaking forest that stretches seven thousand miles around our planet and contains 1/3 of all trees on earth.

当南方温暖潮湿的空气遭遇极地的寒冷,天空出现了由湿气形成的冰晶及雪花。每一片水晶都是由灰尘粒子组成。两者都是对称的六边形,但没有两片是一模一样的形状。他们的多样性和复杂性令人为之惊讶。每片雪花都是等着春天被释放的水。因为这个原因,雪是这些静默森林及一切在这里以这样或那样的方式生存生命的源泉。一些动物,比如这头灰色猫头鹰,在春天万物复苏时出现,然后像幽灵般消失。而其他动物,就像其猎物一样,常年在雪下隔绝上面的冷空气。北方森林主要由季节性的游客和北极专家组成。但是却远不止此。他们一起构成了一个绵延七千英里的不可侵犯的森林,包含我们这个星球所有的树木的1/3。