He'd seen the proof in black and white.

他已经见到书面证据了。

《柯林斯英汉双解大词典》

These ironclad details are irrefutable proof in black and white.

白纸黑字，铁证如山。

《新英汉大辞典》

Finally he said that his very presence in africa-a black senator from the United States — provided living proof that humanity was moving forward.

最后他说，他在非洲此刻的存在- - -来自美国的黑人参议员——提供了生动的证明人类是向前推进的。

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No one there had any inkling of the desperate scene unfolding just beyond Kiss' black, sound-proof double doors, said taxi driver Edson Schifelbain, who was in his car, waiting for passengers.

NPR: No Alarm, Only 1 Exit In Brazil Nightclub Fire

Jourden explains how the wires that clutter most contemporary bike fronts have been run ingeniously inside the handlebars, leaving one to admire the bike's clean, low-slung lines, painted in the handsome, scratch-proof matte black that distinguishes so many of their bikes.

WSJ: Bespoke Wheels | Making It

But my observation - and I wasn't with the publication at that time - was that somehow President Obama's defense of Professor Gates was finally, for some people, proof that President Obama was really black.

NPR: 12 min 17 sec