在很大程度上，Roids 只是小行星和彗星的小碎片。
Roids are, for the most part anyway, they are just smaller bits of 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。
The solar system also has two analogous classes of objects, smaller than planets—namely, asteroids and comets.
探索一颗小行星和彗星们的相互作用。
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