and silently pursuing their prey through the undergrowth. 以及悄无声息地 在下层灌木丛中追捕猎物

260. They lost the arms and legs of their reptilian ancestors
     它们失去了爬行动物祖先的四肢
261. and developed a streamlined body...
     并发展出流线型身体
262. making them perfectly adapted to hunting in burrows
     使它们完全适应了在洞穴中捕猎
263. and silently pursuing their prey through the undergrowth.
     以及悄无声息地 在下层灌木丛中追捕猎物
264. But young mammals aren't entirely helpless.
     但是哺乳动物幼崽并非完全无助
265. They have their mothers to look after them.
     它们有母亲来照顾自己
266. She spots the danger...
     它发现危险

来自《我们星球上的生命 第一季 第五集 Life on Our Planet S01E05 巨兽阴影下》第 263 行