每次说到动物的活动——无论是踱步、奔跑抑或只是静止不动，我们总是注意到这些活动中四肢骨骼及肌肉的变化。

When we think about animal locomotion... whether it's walking, running, or just standing around... we usually focus on the bones and muscles in the legs and feet.

youdao

海龟颈部和四肢的肌肉及骨骼的特殊设计使它能把暴露在外的部分缩回去，这样攻击者只能去咬坚硬的外壳。

The particular design of muscles and bones in the neck and limbs of the turtle allow that it can draw in its exposed parts such that an attacker can find nothing but hard shell to bite.

youdao

当骨骼和肌肉及脂肪的体积增加过超过了皮肤的延长的速度，真皮的弹力纤维就会被拉断而形成纹路。

Had increased to exceed cutaneous prolate rate when skeleton and muscle and adipose bulk dermal bounce fiber can be pulled and form grain.

youdao