Supporters stand on a truck during a campaign rally of presidential election candidate Morgan Tsvangirai in Chitungwiza of Harare, capital of Zimbabwe, July 28, 2013. Zimbabweans are expected to vote on July 31 to choose a president, legislators, and local councilors. Incumbent President Robert Mugabe and Prime Minister Morgan Tsvangirai are considered the main contenders for the presidency. (Xinhua/Meng Chenguang)