1·Roids are, for the most part anyway, they are just smaller bits of asteroids and comets.
在很大程度上，Roids 只是小行星和彗星的小碎片。
2·So to talk about where meteorites come from, we need to talk about comets and asteroids.
那么讲到流星体从何而来，我们就需要讨论下彗星和小行星。
3·I'm not going to go into any depth on comets and asteroids now, but we'll come back later and do that.
我现在不打算深入讨论彗星和小行星了，但是我们稍后会再回到这个点上，讨论这方面的内容。
4·We think meteors that crashed into the moon or tails of passing comets may have introduced water molecules.
我们认为，撞击月球的流星或经过的彗星尾巴可能会留下一些水分子。
5·The solar system also has two analogous classes of objects, smaller than planets—namely, asteroids and comets.
太阳系也有两类类似的物体，比行星还小——即小行星和彗星。