Female students lie on a playground during an event at a university in Wuhan City, the capital of Central China’s Hubei Province, May 25, 2016. The event was organized by the university’s psychology association and was aimed at raising awareness of sleep quality among students and the benefits of forming healthy habits. Photo: China News Service

Female students lie on a playground during an event at a university in Wuhan City, the capital of Central China’s Hubei Province, May 25, 2016. The event was organized by the university’s psychology association and was aimed at raising awareness of sleep quality among students and the benefits of forming healthy habits. Photo: China News Service

Female students lie on a playground during an event at a university in Wuhan City, the capital of Central China’s Hubei Province, May 25, 2016. The event was organized by the university’s psychology association and was aimed at raising awareness of sleep quality among students and the benefits of forming healthy habits. Photo: China News Service

Female students lie on a playground during an event at a university in Wuhan City, the capital of Central China’s Hubei Province, May 25, 2016. The event was organized by the university’s psychology association and was aimed at raising awareness of sleep quality among students and the benefits of forming healthy habits. Photo: China News Service