A student disinfects her hands when entering a primary school in Shanghai, east China, Feb. 22, 2021. Primary and middle schools in Shanghai started the new semester on Monday. (Xinhua/Ding Ting)

A man receives temperature checking when entering a primary school in Shanghai, east China, Feb. 22, 2021. Primary and middle schools in Shanghai started the new semester on Monday. (Xinhua/Ding Ting)

Students receive temperature checking when entering a primary school in Shanghai, east China, Feb. 22, 2021. Primary and middle schools in Shanghai started the new semester on Monday. (Xinhua/Ding Ting)