An activity is held to mark World Children's Day 2019 at a park in Changsha, central China's Hunan Province, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Chen Zeguo)

An activity is held to mark World Children's Day 2019 at a square in Bao'an District of Shenzhen, south China's Guangdong Province, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Mao Siqian)

The National Aquatics Center, or the "Water Cube", exhibits the numbers "1120" along with blue lighting to mark World Children's Day 2019 in Beijing, capital of China, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Zhang Yuwei)

A high-rise building exhibits blue lighting to mark World Children's Day 2019 in Changsha, central China's Hunan Province, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Chen Zeguo)

An activity is held to mark World Children's Day 2019 at the Olympic Park in Beijing, capital of China, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Zhang Yuwei)

The Chongqing World Financial Center (the tallest building visible) exhibits special lighting to mark World Children's Day 2019 in southwest China's Chongqing, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Wang Quanchao)

An activity is held to mark World Children's Day 2019 at a square in Bao'an District of Shenzhen, south China's Guangdong Province, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Mao Siqian)

An activity is held to mark World Children's Day 2019 at the Olympic Park in Beijing, capital of China, Nov. 20, 2019. Activities were held across China on the occasion of World Children's Day 2019, which fell on Wednesday. (Xinhua/Zhang Yuwei)