To avoid detection, the crocodile silently submerges... 为避免被发现 鳄鱼悄无声息地潜入水中

247. But it doesn't matter.
     但是没关系
248. The Nile crocodile knows the wildebeest will return...
     这只尼罗鳄知道角马♥会♥回来
249. just as they always have.
     它们总会回来
250. To avoid detection, the crocodile silently submerges...
     为避免被发现 鳄鱼悄无声息地潜入水中
251. holding its breath
     屏住呼吸
252. for up to an hour.
     长达一小时
253. Crocodiles can slow their heart rate to just two beats a minute...
     鳄鱼能够将心跳降至每分钟两次

来自《我们星球上的生命 第一季 第四集 Life on Our Planet S01E04 冷血动物》第 250 行