Aerial photo taken on Nov. 20, 2020 shows buildings lighting up blue on the occasion of World Children's Day in Gu'an County, north China's Hebei Province. Buildings and iconic monuments in some Chinese cities went blue on Friday to celebrate World Children's Day. World Children's Day is celebrated on November 20 each year to promote international togetherness, awareness among children worldwide, and improving children's welfare. (Photo by Men Congshuo/Xinhua)
