Our immune system's function is to keep us healthy in the face of an environment where there are lots of things that could potentially harm us.

我们免疫系统的功能就是保持自身健康,在面对危机四伏的环境时,使我们免受伤害

耶鲁公开课 - 生物医学工程探索课程节选

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