polish this paragraph: But sometimes working hard is not always a good thing. Effort sometimes means that we need to devote time to completing the task, and studying or working for a long time will make our body tired, such as dizziness, back pain and so on. These tiredness can affect our state, reduce our learning and work efficiency, and make efforts have the opposite effect, or even worse than working on a routine Write your response with exactly 5 paragraphs, separated with the markdown divider: ***.
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