It started life as a seed some 200 years ago. 约200年前 一枚种子根植地下
where life on Earth first began four billion years ago. 生命正是起源于类似这样的喷口
Not so long ago, these whales faced a graver threat. 不久之前 这些鲸鱼面临着更严重的威胁
But 40 years ago, commercial whaling was banned. 但40年前 商业捕鲸被禁止
has come from a single invention made less than 140 years ago. 是由一项历史还不到一百四十年的发明引起的
Introduced here just 40 years ago, 虽然才被引入此地四十年
300 years ago, this Hura tree began its race for light. 三百年前这棵响盒子就开始努力汲取阳光
Meadows that only a few weeks ago were buried beneath the snow 几周前还深埋在冰天雪地里的牧场