Us President Barack Obama listens to Stephanie Bullock (R) who is part of a team from the US Virgin Islands that design rockets for the Team America Rocketry Challenge, during the 2015 White House Science Fair, a celebration of students winners of STEM (Science, technology, engineering and math) competitions from across the country at the White House, in Washington, DC on March 23, 2015. (Photo by Aude Guerrucci/WHITE HOUSE POOL (ISP POOL IMAGES)/Corbis/VCG via Getty Images)
