U.S. President Obama Tuesday urged students to take responsibility for their educational choices because "nobody gets to write your destiny but you." Speaking at the Julia R. Masterman Laboratory and Demonstration School, a 2010 National Blue Ribbon School in Philadelphia, Obama in his back-to-school message said that as a parent and one-time student, he understood some of the feelings students feel at this time of year."You're a little sad to see the summer go, but you're also excited about the possibilities of a new year," he said. "But I know some of you may also be nervous about starting a...