Once upon a time, this defense would have worked. 在过去 这种防御会有效果
they are rarely the top predators their towering ancestors once were... 它们却极少像高大的祖先那般 成为顶级捕食者
For the inhabitants of Earth's once tropical waters, 过去地球上热带水域的“居民们”
With the coast clear, the trilobite continues on its merry way once more. 威胁消除之后 三叶虫继续踏上快乐的旅程
whose ancestors once roamed on land. 它的祖先曾遍布陆地
They once more cover 65% of the country. 森林又一次覆盖了韩国的65%
The once mighty river Jordan is now just a trickle. 曾经宽阔的乔丹河现在只是条小溪