But there's this one phylum of worms, the annelids, that can re-grow unlike anything else that we've ever seen in the kingdom.

但有一类子——环节动物子——可生长，不同于我们在动物界见的任何其它生物。

Worms from the phylum Nematoda or the phylum  Annelida have some sort of body cavity— a fluid-filled space between the body  wall and the digestive tract that helps transport nutrients and corresponds to  the development of more complex systems.

线环节动物的蠕具有某种体腔——体壁和消化道之间的充满液体的空间，有助于运输营养物质并与更复杂系统的发展相对应。