Otherwise, statisticians say only strict clinical trials with a control group and a test group and one variable can truly prove a cause-and-effect association.

否则，统计学家表示只有进行严格的临床试验，对比一个控制组、一个测试组以及一个变量，才能真正证明因果关系。

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CONCLUSION: Scientific and strict clinical trials of drugs are helpful to obtain actual and reliable research results.

结论：科学、严谨的药物临床试验设计，有助于获得真实、可靠的研究结果。

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But that is a reason for keeping clinical trials strict.

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But such trials typically have strict enrollment criteria and findings often can't be generalized to the broader population.

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The strict reporting restrictions both before and during trials, the absence of television cameras and the rule against jurors speaking to anyone after a verdict would seem secretive to an almost sinister degree, inviting miscarriages of justice rather than serving as guarantees against them.

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