Aerial photo taken on March 27, 2021 shows fog-shrouded buidings in Tianjin, north China. (Xinhua/Zhao Zishuo)

Aerial photo taken on March 27, 2021 shows the landmark Tianjin Television Tower shrouded in fog in Tianjin, north China. (Xinhua/Zhao Zishuo)

Photo taken on March 27, 2021 shows people and vehicles crossing a bridge amid fog in Tianjin, north China. (Xinhua/Sun Fanyue)

来源：Xinhua