你无须多言， 行动是最有力的证明。

You needn't say much – actions speak a lot louder than words.

youdao

所以证书是最有力的证明。

So certificate would be the most powerful certification.

youdao

他很快答到：“价格，如果我们了解一下烟草行业就会发现，价格是减少消费最有效的唯一方法，我认为强有力的证据能够证明苏打税会非常有效果。”

He responded quickly: "Price, if we learned from tobacco, is the single most effective way of reducing consumption, and I think there's strong evidence that a soda tax would be very effective."

youdao