I have read that it takes 21 days for a habit to take effect, which is why I mention a 30 day period of testing anything new.

我曾经读到过，要培养一个习惯，需要21天，这也就是为什么我提出用30天的时间来尝试新的改变。

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These men undergo a long period of testing and training.

这些人要经受长期的测试和训练。

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These men undergo a long period of testing and training.

这些人要经受长期的测试和训练。

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