A pupil tries a plasma magic ball under the instruction of volunteers in Cixi City, east China's Zhejiang Province, July 22, 2019. A volunteer center in Cixi City opened science courses for local pupils to help them learn scientific knowledge and enrich their summer vacation. (Xinhua/Xu Yu)

A pupil tries a scientific instrument under the instruction of a volunteer in Cixi City, east China's Zhejiang Province, July 22, 2019. A volunteer center in Cixi City opened science courses for local pupils to help them learn scientific knowledge and enrich their summer vacation. (Xinhua/Xu Yu)

Pupils learn how to do CPR under the instruction of a volunteer in Cixi City, east China's Zhejiang Province, July 22, 2019. A volunteer center in Cixi City opened science courses for local pupils to help them learn scientific knowledge and enrich their summer vacation. (Xinhua/Xu Yu)