Two men inspect the goods at at Farma, a marijuana dispensary in Portland, Oregon. The state's first week of retail sales brought in an estimated $11 million, a trade group says. Josh Edelson/AFP/Getty Images hide caption

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Partygoers attend a Prohibition-era themed New Year's Eve party celebrating the start of retail pot sales, at a bar in Denver on Dec. 31, 2013. Brennan Linsley/AP hide caption

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Deuel County Sheriff Adam Hayward shows off a container of confiscated marijuana in Chappell, Neb., in July. Nikki Kahn/The Washington Post/Getty Images hide caption

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Officials in Aspen have put out a brochure on how to use marijuana safely and legally. Marci Krivonen hide caption

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Trimmers prepare the marijuana flower, or bud, to make it more appealing to consumers. They use scissors to snip off the leaves and stems. Brett Myers/Youth Radio hide caption

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Brooke Gehring, CEO of Patients Choice and Live Green Cannabis, stands in one of her company's grow houses in Denver. Kirk Siegler/NPR hide caption

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Edibles available at LoDo Wellness Center, a retail marijuana and medical marijuana dispensary and grow facility in downtown Denver. Matthew Staver/Landov hide caption

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Amber McGowan, left, and Krystal Klacsan work Monday at Cannabis City in Seattle, a day before the store is to begin legal pot sales on Tuesday. The store will be for now the only one in Seattle to sell recreational marijuana. Ted S. Warren/AP hide caption

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