Sporadic dengue fever outbreaks in Florida in 2009 and 2010 spurred mosquito control efforts in Key West and Miami Beach, shown here. The same mosquito that carries dengue, Aedes aegypti, can transmit Zika. Joe Raedle/Getty Images hide caption

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The Noor I Concentrated Solar Power plant, shown on Thursday, is the first phase of a large solar thermal power plant that is intended to supply more than a million Moroccans with electricity. Fadel Senna/AFP/Getty Images hide caption

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Food writer Bee Wilson says that babies are most open to trying new flavors between the ages of 4 and 7 months. Duane Ellison/iStock hide caption

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Amelia Westerdale works with physics students during a tutorial session at the University of Colorado Boulder. Westerdale is part of the Learning Assistant Program, tasked with helping to coach and tutor students. Theo Stroomer for NPR hide caption

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When so-called senescent cells were removed from mice, they were healthier and lived longer than mice that still had the cells. Philippe Merle/AFP/Getty Images hide caption

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This San Francisco home collapsed in the 1989 Loma Prieta earthquake, which also claimed dozens of lives. ADAM TEITELBAUM/AFP/Getty Images hide caption

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An adult spirit bear crosses a fallen log over a stream in the Great Bear Rainforest in British Columbia. Barcroft Media/Barcroft Media via Getty Images hide caption

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Alchemist Hennig Brand looks focused, if maybe a bit drained, in this 1795 painting by Joseph Wright. The painting depicts Brand's discovery of the chemical element phosphorus. Joseph Wright of Derby/Wikimedia hide caption

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Pallets of bottled water are seen ready for distribution in a Flint, Mich., warehouse on Jan. 21. The warehouse is the emergency water supply for Flint residents affected by lead-contaminated water. Sarah Rice/Getty Images hide caption

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Kelli Fabick of Ellisville, Mo., held her mother's Australian silky terrier, Zoey, as veterinarian Sarah Hormuth gave the dog a flu shot last April. The dog flu strain H3N2 is now circulating in more than two dozen U.S. states. St. Louis Post-Dispatch/TNS via Getty Images hide caption

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