Aerial photo taken on May 1, 2019 shows Guanshanhu district shrouded in fog in Guiyang, southwest China's Guizhou Province. (Xinhua/Liu Xu)

　　Aerial photo taken on May 1, 2019 shows Guanshanhu district shrouded in fog in Guiyang, southwest China's Guizhou Province. (Xinhua/Liu Xu)

　　Aerial photo taken on May 1, 2019 shows Guanshanhu district shrouded in fog in Guiyang, southwest China's Guizhou Province. (Xinhua/Liu Xu)

　　Aerial photo taken on May 1, 2019 shows Guanshanhu district shrouded in fog in Guiyang, southwest China's Guizhou Province. (Xinhua/Liu Xu)

　　Aerial photo taken on May 1, 2019 shows Guanshanhu district shrouded in fog in Guiyang, southwest China's Guizhou Province. (Xinhua/Liu Xu)