The tragic history of colonial people, the endless conflict between major powers, especially the two world wars, have left painful lessons in the history of mankind.

殖民地人民的悲惨历史，大国间连绵不断的冲突，特别是两次世界大战，都给人类留下了沉痛的历史教训。

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All that fretting and worrying teaches you nothing, but experience, the constant trainer, provides you with an endless stream of lessons and ideas for new projects and new directions.

因为所有的恐惧害怕都不能教会你任何东西，但是经验，不断的练习却可以带来无尽的教训，提供新的主意并指引新的方向。

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Long hours and endless repetition of dry lessons yields little tangible result in terms of ability to use the language.

超长的学习时间，无休止地重复枯燥的课程，实际上对提高英语的应用能力收效甚微。

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