They also had many more replacement teeth growing beneath the working tooth.

他们还在工作牙齿下方长出了更多的替代牙齿。

But after those adult teeth grow in, all the stem cells that laid down the crystal nanorods self-destruct, so that's the only set of replacement teeth you get.

但当这些恒牙长出后，所有生成纳米结晶体的干细胞就会自我消亡，所以你只能有这一副替换牙。

A large hadrosaur had around a thousand teeth in its mouth at any one time, if you include both the teeth being actively used in eating as well as all the replacement teeth.

一只大型鸭嘴龙在任何时候的嘴里都有大约一千颗牙齿，如果你把用于进食的牙齿和所有替换的牙齿都包括在内的话。