instruction:
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.
question:
Question: Jeff is stopping exercising his muscles at home. Over time his muscles will grow 
 Answer: smaller
answer:
Muscles that are exercised are bigger and stronger than muscles that are not exercised.


question:
Question: Simon was digging in his yard and found that the rocks that were deeper in the ground, compared to the surface rocks, were likely 
 Answer: older
answer:
Therefore, deeper rock layers must be older than layers closer to the surface.


question:
Question: If Jim stop exercising his muscles, would the strength of them 
 Answer: decrease
answer:

Exercising muscles increases their size, and bigger muscles have greater strength.