正因为缺少因果联系，目前并没有结论性的证据来支持通过手术闭合卵圆孔有助于降低偏头痛发作频率的说法。

Because of this lack of a causal relationship, there is currently a lack of conclusive evidence that supports having a surgical procedure to close a P.F.O. as a means to reduce migraine frequency.

youdao

由于这问题的证据还不是结论性的，而且常常是矛盾的，所以就难以断定有关电力对身体的影响的顾虑是合乎情理，还是毫无根据的怀疑。

Because evidence on the subject is inconclusive and often contradictory, it has been hard to decide whether concern about the health effects of electricity is legitimate-or the worst kind of paranoia.

youdao

精英阶层观点的转变与缺乏结论性的学术证据不无关系，没有证据证明过去十年涌入英国的移民像传说的那样成为促进经济的力量。

This change in elite opinion has something to do with the lack of conclusive academic evidence that the past decade’s influx has been the economic boon it was cracked up to be.

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