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.

Q: Question: If a device were to become less efficient, it would produce _____ usable energy. 
 Answer: less

A: The more efficient a device is, the greater the percentage of usable energy it produces.
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Q: Question: Dan needs to stay warm in the woods, and can bring one animal for body heat to sleep next to him. Given the choice between a horse and cat, Dan will choose the 
 Answer: horse

A: Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed.
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Q: Question: DJ has a solution that he adds particles to. The solution is now a _____ concentration. 
 Answer: higher

A:
At higher concentrations, particles of reactants are crowded closer together, so they are more likely to collide and react.
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