北极熊必须走得更远，并更加努力地寻找食物。
Polar bears have to go further and work harder to find food.
总之，看书和实践经验是共存的并一起起着重要的作用。有了他们的帮助，人们可以走得更远更深入。
To sum up, reading books and the practical experience exist side by side and play an important part together. People can go farther and further with their help.
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