Activity To model how particles move as states of matter change, Jelani filled a clear box with as many marbles as the box would hold. Then he drew a picture of what the box looked like with the marbles in it.
Part C
Think back to the three models of matter in parts A and B. Which model had a definite shape? Explain.

I think the third one

Explanation:

Because, the third model is filled to the top of the container and  has, made the definite shape of it ( the container)

in 1859, charles darwin set out his theory of evolution by natural selection as an explanation for adaptation and speciation. he defined natural selection as the "principle by which each slight variation [of a trait], if useful, is preserved".