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.
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Question: Question: Milo was moving some metal balls around. If he were to move the balls closer together, what would happen to the force of gravity? 
 Answer: increase

Answer: Objects that are closer together have a stronger force of gravity.


Question: Question: A piece of glass has _____ friction than a piece of sandpaper. 
 Answer: less

Answer: Rougher surfaces have more friction between them than smoother surfaces.


Question: Question: In the past, solar power was _____ than it is today. 
 Answer: more expensive

Answer:
Solar power is expensive, but as demand increases technology improves and costs decrease.