If the hair bulb is damaged, the hair may not grow back.

如果毛球受损，头发可能不会再长出来。

BB:Yeah. Ouch. Those do not grow back, y'know.

是啊。哎。你知道的，那些东西可长不回来啦。

BB: Yeah. Ouch. Those do not grow back, y'know.

是啊。哎。你知道的，那些东西可长不回来啦。

How can a fractured limb grow back to its former strength?

骨折的四肢是怎样重新获得之前的力量呢？

The thing is, it's not just neurons that need to grow back.

问题是，不仅仅是神经元需要再生。

I can remember wondering if the bark would ever grow back.

我还记得当时我很好奇，想看看树皮究竟还能不能重新长好。

Since the heart can't grow back new muscle, it heals by scar formation.

因为心脏不能长出新的心肌，它通过形成疤痕而愈合。

Generally, when and if your hair ever does grow back, it might fall out again later on.

一般来说，当你的头发重新长出来的时候，它可能会在以后再次脱落。

This is somewhat like a lazy cow that waits for the grass under its mouth to grow back.

就像一头懒牛等着它嘴下的那块草长回来。

They grow back faster and fuller and make more seeds than they would have if left alone.

比起没被碰过的状态，它们生长得更快，更饱满，种子也结得更多。