- a handful of pups await her return.
许多幼崽在等待它的归来 - Crucial to the success of mammals
哺乳动物成功的关键是 - was the evolution of parental care.
父母照护的进化 - Giving birth to live young
生下活的幼崽 - and nourishing them on their mother's milk
用母亲的乳汁滋养幼崽 - until they reach independence.
直到其独♥立♥ - But for these nervous little youngsters...
但对于这些紧张的幼崽们来说