我们不是只做了一组临床试验，我们有两组以供对比。

Not only do we have one clinical trial, we have two.

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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。

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.

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“通过擦洗去掉粉刺的做法是不对的，”哈佛大学皮肤病临床试验研究组主任皮肤病学者亚里克斯•波尔•金博表示。

“The concept that you can wash away your acne is not based on true fact,” said dermatologist Alexa Boer Kimball, director of Harvard University's Clinical Unit for Research Trials in Skin.

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