It may not be long before we witness the extinction of one of the world's six species of tigers, the Amur (or Siberian) tiger (Panthera tigris altaica).
东北虎（也叫西伯利亚虎）是世界上的六种老虎之一，我们目睹它们绝种的日子将不再遥远了。
Once every 100 million years or so, an even larger asteroid may cause a mass extinction; most scientists believe a six-mile-wide asteroid doomed the dinosaurs 65 million years ago.
每隔1亿年左右，一颗更大的小行星可能导致物种大灭绝。大多数科学家相信一颗6英里直径的小行星在6500万年前使恐龙灭绝。
Once every 100 million years or so, an even larger asteroid may cause a mass extinction; most scientists believe a six-mile-wide asteroid doomed the dinosaurs 65 million years ago.
每隔1亿年左右，一颗更大的小行星可能导致物种大灭绝。大多数科学家相信一颗6英里直径的小行星在6500万年前使恐龙灭绝。
应用推荐