Employees work at a sorting centre of Zhongtong (ZTO) Express ahead of the Singles Day shopping festival, Chaoyang District, Beijing, November 8, 2015. On China's giant Singles Day internet shopping festival, the country's delivery firms are stretched so thin that they are looking for tie-ups, listings and new investors to husband their resources. (Photo by Jason Lee/Reuters)

Tourists standing near the sea shore are hit by a wave, which surged past a barrier under the influence of Typhoon Chan-hom, in Qingdao, Shandong province, China, July 12, 2015. One of the most powerful typhoons to strike eastern China in decades disrupted air, rail and sea transport on Saturday after forcing the evacuation of more than a million people from the provinces of Zhejiang and Jiangsu, state media reported. (Photo by Reuters/Stringer)

Local residents crowd a swimming pool during a hot weather in Suining, Sichuan province, 27 July 2008. (Photo by Reuters/Stringer)

Monks take pictures with their mobile phones of the mummified body of a monk at Puzhao temple in Quanzhou, Fujian Province, China, January 10, 2016. According to local media, the monk named Fuhou died three years ago at the age of 94 and his remains was placed in a vat and turned into a mummy as a sign of respect. (Photo by Reuters/Stringer)

A rescuer saves a resident from a flooded area in Wuhan, Hubei Province, China, July 2, 2016. (Photo by Reuters/China Daily)

Models promote a condom brand at the first Shenzhen s*x Culture Festival on September 21, 2007 in Shenzhen of Guangdong Province, China. The festival aims to increase awareness about reproductive health and popularise s*x education. (Photo by China Photos/Getty Images)

Rescuers work at the accident scene on a bridge on July 24, 2011 in Wenzhou, Zhejiang Province of China. The train from Hangzhou to the city of Wenzhou derailed on a bridge that is 10 m above the field in Shuangyu Town of Wenzhou city at 8:34 p.m on Saturday. The first four coaches and the 15th and 16th coaches of the train went off the line killed 32 and injured 191 people. (Photo by ChinaFotoPress/Getty Images)

A Chinese girl peeps at Santa at a shopping center on Christmas Eve December 24, 2011 in Beijing, China. Though Christmas is not officially celebrated in China, the holiday is becoming increasingly popular as Chinese adopt more Western ideas and festivals. (Photo by Feng Li/Getty Images)