Solid, liquid, gas ^^
For example, if you have an ice cube you have a solid piece of matter, but if you heat it up it melts and then it's liquid, and after getting hot enough it evaporates and even though you can't see it it's still there, but as a gas.
By the way, what's this have to do with Spanish?
Answer:
Nosotros barremos el suelo "we sweep the floor."
Explanation:
Prendemos would mean "we light the ground," sacuden would mean "we shake the ground," and barren is the incorect verb form. Barren is used for ustedes, and in this situation we are reffering to ourselves and not somebody else.