Children hold the National 9/11 Flag in front of the National September 11 Memorial Museum in New York, the United States, May 21, 2014. The memorial museum on Wednesday opened to the general public after a ceremonial transfer of the National 9/11 Flag, an American flag that had flown at 90 West Street, adjacent to Ground Zero, for weeks after the attacks, into the museum's permanent collection. (Xinhua/Wang Lei)
