Policeman Shi Xianqiang and his wife Shen Xin explain border laws to a tourist at Luoguhe Village in Beiji Town of Mohe City, northeast China's Heilongjiang Province, July 22, 2020. Shi Xianqiang and his wife are both police officers responsible for patrolling the border between China and Russia at Luoguhe, one of China's northernmost villages. (Xinhua)