你可以从你的骨骼和肌肉中感受到它。

You can feel it in your bones and muscles.

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当上了年纪的时候，你的骨骼会变薄变弱。

Your bones become thinner and weaker as you age.

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另外一个好处：钙有助于保持你的骨骼强壮。

Another benefit: the calcium will help keep your bones strong.

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Well, you could think about the cell wall of a bacterium as its skeleton, it's what protects it from mechanical forces that are out in the world.

你可能认为细菌的细胞壁,就像骨骼一样,使其免受,外界机械力的伤害

耶鲁公开课 - 生物医学工程探索课程节选