U.S. Democratic Presidential Candidate Hillary Clinton (L) and Vice Presidential Candidate Tim Kaine take the stage at the end of the 2016 U.S. Democratic National Convention at Wells Fargo Center, Philadelphia, Pennsylvania, the United States on July 28, 2016. Former U.S. Secretary of State Hillary Clinton on Thursday formally accepted the Democratic Party's nomination for president and pledged more economic opportunities for Americans and "steady leadership." (Xinhua/Li Muzi)