In this task, you are given a question and answer for that. The answer will fill in the blank or will complete the unfinished question. Your task is to provide an explanation based on the given question or fill-in-the-blank statement, and answer.

[EX Q]: Question: Olive and Jean were collecting rocks during a hike, they collected too many rocks so the two girls decided to leave some rocks behind to come back to later. Olive decided to bury her rocks in the dirt, and Jean decided to leave hers in a ditch in the sun. When they returned a week later, which girl's rocks changed the most? 
 Answer: Olive
[EX A]: With more surfaces of the rocks exposed, there are more places for chemical weathering to occur.

[EX Q]: Question: If Milo's country begins decreasing the size of its population, what happens to its growth rate? 
 Answer: it decreases
[EX A]: With exponential growth, the population starts out growing slowly. As population size increases, the growth rate also increases.

[EX Q]: Question: Sean is trying to see how fast the water molecules are moving in a container of water. He observes that the molecules are moving very quickly, so the temperature must be 
 Answer: warm
[EX A]:
When a volume of water is cooled, the molecules move less vigorously, so same number of molecules takes up less space and the water is denser.