Being endothermic is a lot of work.

那就是成为内温动物要付出太多了。

And flying takes a lot of energy too, so being endothermic would have helped.

飞行也挺消耗能量，所以也促使它们成为了内温动物。

The hottest 20 percent of endothermic mammals keep their bodies higher than 37.9 C.

前 20% 体温最高的内温哺乳动物体温超过了 37.9 摄氏度。

Endothermic creatures are special because they create enough internal heat to keep their body temperature above their environment.

内温动物很特别，它们体内能产生足够的热量使它们的体温能保持在高于环境的温度。

And by the late Cretaceous, birds were fully endothermic.

到白垩纪晚期，鸟类完全吸热。

And since exothermic reactions produce heat, that heat tends to favor the reverse endothermic reactions.

由于放热反应会产生热量， 因此热量往往有利于反向吸热反应。

Leatherbacks, though not exactly endothermic, can be considered Gigantothermic.

棱皮龟虽然不完全是吸热动物，但可以被认为是巨温动物。

So some dinosaurs appear to have endothermic traits, while others have signs of being ectothermic.

因此，一些恐龙似乎具有吸热特性，而另一些则具有变温的迹象。

A much more interesting reaction involves 2 different ions of cobalt that reach equilibrium in an endothermic reaction.

一个更有趣的反应涉及两种不同的钴离子， 它们在吸热反应中达到平衡。

How did a group of animals completely reorganize its physiology to go from mesothermic to endothermic?

一群动物如何完全重组其生理机能，从温热状态转变为吸热状态？