Mammals expend huge amounts of energy just keeping warm .

哺乳动物仅为保暖就需要耗费大量能量。

Only mammals attempt to preserve every life .

只有哺乳动物会试图保护每一条生命。

That is a pattern rarely found in mammals .

而那是在哺乳动物中很少见的。

Mammals carry dozens of protocadherin genes .

哺乳动物携带数十种原钙粘蛋白基因。

They are truly beautiful , mysterious mammals .

它们是真正美丽而又神秘的哺乳动物。