Attendees visit the Ford booth during Auto China 2018 show held in Beijing, China, Wednesday, April 25, 2018. Auto China 2018, the industry's biggest sales event this year, is overshadowed by mounting trade tensions between Beijing and U.S. President Donald Trump, who has threatened to hike tariffs on Chinese goods including automobiles in a dispute over technology policy. (Photo by Ng Han Guan/AP Photo)

A woman is dragged away by Chinese men moments after she was seen talking to journalists near the site of a reported explosion outside the U.S. Embassy in Beijing, China, Thursday, July 26, 2018. A man exploded a small homemade bomb outside the U.S. Embassy in Beijing on Thursday, injuring only himself, according to police and an embassy spokesperson. (Photo by Ng Han Guan/AP Photo)

In this Friday, March 3, 2017 photo, a ribbon on a staff member's outfit blows in the breeze as she arrives for the opening session of the Chinese People's Political Consultative Congress (CPPCC) at the Great Hall of the People in Beijing. The annual session of China's ceremonial legislature is designed to awe onlookers with its size and sweep, yet the experience is also made up of tiny moments, details that point to the personalities of the participants and the event's unique, sometimes quirky, traits that a casual observer might easily miss. (Photo by Mark Schiefelbein/AP Photo)

Chinese archaeologists announced the discovery of 110 life-sized terracotta warriors, guarding the tomb of Qin Shi Huang, China's first emperor.

Photo: Archaeologists work on a terracotta warrior in the third excavation of pit one at the Terracotta Warriors and Horses Museum in Xi'an in northwest China's Shaanxi province Saturday, June 9, 2012. (Photo by AP)

The 2012 Magic Art Special Exhibition Of China is now open at the Hangzhou Peace International Exhibition and Conference Centre of the Chinese city of Hangzhou.

Photo: Visitors poses with a 3D painting during a show featuring over 50 such works in China on July 20, 2012. (Photo by Associated Press)

A performer plays the role of the Emperor during a re-enactment of an ancient ceremony of Qing Dynasty Emperors praying at Ritan Park which holds the ceremony of 'fete day'' to mark the first day of spring on March 21st, 2011 in Beijing, China. March 21st is the Day of Vernal Equinox according to the Chinese lunar calender. (Photo by Lintao Zhang/Getty Images)

Chinese artist Kong Ning walks in her costume made of hundreds of orange plastic blowing horns during her art performance raising awareness of the hazardous smog in front of the Drum tower in a historical part of Beijing on a very polluted day December 7, 2015. Kong, whose works include themes related to China's air pollution problem, named her new performance “The Orange Horns Bride Marries the Blue Sky” and presented it dressed in orange, the colour of the second highest pollution alert level issued again in Beijing as hazardous smog blankets the capital. (Photo by Damir Sagolj/Reuters)

Chinese artist Kong Ning poses in a costume symbolizing a butterfly, which is decorated with 365 masks on its wings to represent the number of days in a year, during her performance art at the Badaling section of the Great Wall on the outskirts of Beijing January 1, 2015. Kong, whose works include themes related to China's air pollution problem, named her new performance art “Hua Die” (transforming into a butterfly) and performed it on the first day of the new year as she hopes that China has clean air for this year. (Photo by Kim Kyung-Hoon/Reuters)