Until the eighteenth century, people relied on energy derived from plants as well as animal and human muscle to provide power.

直到18世纪，人们还依赖于来自植物、动物和人类肌肉的能量来为自身提供动力。

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To show its power, the scientists printed a jaw bone, muscle, and cartilage structures, as well as a stunningly accurate human ear.

为了展现这一技术的能力，科学家们打印了颌骨、肌肉、软骨组织和人耳进行实验。

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The use of human muscle generates mere fractions of the power required to run these facilities.

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