However, most of its internal heat comes from the action of its muscles.

然而，它的大部分内热来自肌肉活动。

Leatherbacks apparently do not generate internal heat the way we do, or the way birds do, as a by-product of cellular metabolism.

棱皮龟显然不把热量当作新陈代谢的副产品，以我们产生内部热量的方式，或者鸟类产生内部热量的方式来产生出来。

Earth's internal heat, fueled by radioactivity, provides the energy for plate tectonics and continental drift, mountain building, and earthquakes.

地球内部因放射而产生的热量为板块运动、大陆漂移、造山运动和地震提供了能量。