They weigh over a ton and are armed with tusks a metre long. 体重超过1吨, 有长达1米的象牙为武器
0nce an extremely rare sight, polar bears have recently been seen over 60 miles from the shore. 曾经有人在离海岸60英里处发现了北极熊 这种事情是极难碰到的
They have travelled over 5,000 miles to reach these waters. 它们经过5000英里的漫长旅程终于来到了这片水域
The birds have flown inland for over 300 miles to reach this breeding site. 它们往内陆飞行300英里才来到这里繁衍
These are nunataks, the exposed peaks of vast mountain ranges buried in ice over a mile deep. 这些“冰原岛峰”下面是深埋在深达一英里的冰层里的庞大山脉
Instead of waiting for the summer melt, the new arrivals hasten south over the frozen sea. 还没等到夏季解冻期的来临 这些鸟儿就急急忙忙从冰封的海洋赶到南极
but they're just frequent enough to keep life ticking over. 但它们发生的次数 足以保证生命长盛不衰
and reduce visibility for days over areas the size of Britain. 所到之处能见度骤降为零 几天内横扫的地区比英国还大
Each year explorers chart over a hundred miles of new cave passages. 每年 探险家们都会测绘 上百英里新的洞穴通道