Whether or not stretching prevents injuries is difficult to prove. If you stretch too much, or too hard, you actually can increase your risk of injury.

拉伸是否可以预防受伤是难以确认的，如果你拉伸太多，或过度，事实上会增加你受伤的风险。

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It's difficult to get deep, restful sleep on one that's too soft, too hard, too small or too old.

这是很难得到一个深刻的太软，舒适的睡眠，太硬，太小或太旧。

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Too little attention and it's difficult to achieve goals in life, too much attention and it's hard to break free from loops of negative thinking and feeling.

注意力过少的话，难以达到生活中的目标；注意力过多的话，难以从消极感受和思考中逃脱。

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It is hard to build new roads or schools, and far too difficult to fire bad teachers.

ECONOMIST: California on the couch