translation.en: The answer is: long-lived molecules, because if a short-lived molecule undergoes damage, but then the molecule is destroyed -- like by a protein being destroyed by proteolysis -- then the damage is gone, too.
translation.zh: 答案是，长期存在的分子里， 因为如果一个短暂寿命的分子遭到破坏，它将会在寿命完了后被销毁 – 就像蛋白质被水解摧毁 – 累积的损害也一起被销毁了。