Other causes are harder to pin down.

其它原因就很难下定论了。

youdao

But it is harder to pin down more subtle health effects.

但是限制对健康的影响多一点，难度就更大一点。

youdao

Real life skills are harder to measure, harder to pin down, but so much more beneficial.

真正的生活技能难以测量，难以确定，然而却使人受益匪浅。

youdao

Such observations yield a wealth of correlations, but it is much harder to pin down causation.

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But there are other costs as well that are harder to pin down.

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But rare events like those that effect Tysabri are harder to pin down.

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