Volunteers for the first China International Import Expo (CIIE) sing a theme song at an oath-taking ceremony at the National Exhibition and Convention Center (Shanghai) in east China's Shanghai, Oct. 20, 2018. More than 5,000 volunteers for the upcoming CIIE pledged responsibility and commitment during an oath-taking ceremony held here on Saturday. The ceremony also unveiled CIIE volunteers' outfits and a theme song. (Xinhua/Liu Ying)