Mr. Karp: The video ads that we're hit with are always in the form of pre-roll, the video reel you get at the front of an online video.

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In the way that rock and roll started out as a black art form and now it's overwhelmingly white, will one day white rappers be the majority?

NPR: Book Looks at White Youth and Hip-Hop Culture

And no matter what the parents say, you want to document as you're asking and seeing that child roll over, seeing that child walk, seeing that child transfer an object form left hand to right hand.

NPR: Pediatrician: What Parents Should Know About Autism