Chinese peacekeeper Yu Peijie (L) cleans rifles at the camp of Chinese peacekeeping infantry batallion to South Sudan on April 30, 2018. Yu Peijie, 26-year-old, is the leader of the female peacekeeper unit of Chinese peacekeeping infantry batallion to South Sudan. She has a nickname called "Strong Elder Brother". However, she also has a soft heart. This year marks the 70th anniversary of UN peacekeeping. China began its participations in the UN peacekeeping operations in 1990. Today, China has some 2,500 peacekeepers and plays an important role in promoting and maintaining world peace. (Xinhua/Wang Teng)