For example, one thing that could happen is that you build it up with wood and clay, you pick the wrong material for a bridge, and it will not stand up to the forces of nature.

例如,其中的一个问题是,选择了木头和粘土作为造桥的材料,你就选错了材料,这座桥难以与自然力相抗衡

耶鲁公开课 - 生物医学工程探索课程节选

It might bend and bow, that is it's not the forces of nature like the movement of the river that's knocking the bridge down, but it's just the failure of these materials over time, that they don't last as long as they might.

这桥可能会折断,不一定是洪水这样的自然灾害,导致了桥梁的坍塌,可能只是因为建桥的材料老化,这种材料没有那么持久耐用

耶鲁公开课 - 生物医学工程探索课程节选