After being warned by his mother to swear off that demon knuckle cracking, young Donald Unger tested the accuracy of this hypothesis on himself.

自从小时候受到母亲警告说不可以敲打指关节后，小唐就开始在自己的身上测试这种推断的准确性。

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The US researchers behind that study concluded: 'The chief morbid consequence of knuckle cracking would appear to be its annoying effect on the observer. '

这项研究的美国研究员总结道：“掰指关节的主要不良后果在于，关节的响声会让周围的人感到不舒服。”

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The medicine prize went to a physician who, for fifty years, cracked the knuckles on only his left hand to test his mother's contention that knuckle-cracking causes arthritis.

医学奖授给了一位内科医生，他50年来每天不断扳左手手指，以验证自己母亲说扳手指会引发关节炎的话是否正确，他的结论是：妈妈，你错了。

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But after showing all that personality onstage, why didn't he have a reaction when he finally won beyond his familiar knuckle-cracking habit?

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Northern Ireland Secretary Peter Mandelson has appealed to the parties to "knuckle down and get cracking on implementing all aspects of the agreement".

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