People pass a suitcase as they line up to enter a railway station in Beijing, February 15, 2015. Chinese Ministry of Transport said a total of 2.807 billion trips are expected to be made during the 40-day Spring Festival travel rush, which started on February 4 and will last until March 16, Xinhua News Agency reported. (Photo by Reuters/Stringer)

A dancer poses for a photograph as part of the “Dance as Art” photo project in Times Square in New York, on September 22, 2014. (Photo by Carlo Allegri/Reuters)

A general view of Hong Kong's business district is seen Thursday, August 1, 2013. (Photo by Vincent Yu/AP Photo)

This combination of two photos taken on July 5, 2014, shows the Aazzab family waiting to break their fast, top, and their meal, bottom, during the holy month of Ramadan in Casablanca, Morocco. For the millions of Muslims abstaining from food and drink from sunrise to sunset every day during Islam's holiest month of Ramadan, that first sip of water after a grueling fast is by far the most anticipated moment of the day. (Photo by Abdeljalil Bounhar/AP Photo)

In this September 19, 2019 file photo, an aircraft passes the rising sun during take off at the international airport in Frankfurt, Germany. Germany’s top court has ruled that the government has to set clear goals for reducing greenhouse gas emissions after 2030, arguing that current legislation doesn’t go far enough in curbing climate change. (Photo by Michael Probst/AP Photo/File)

Students wearing mask hold hands to surround the St. Stephen's Girls' College in Hong Kong, Monday, September 9, 2019. Thousands of demonstrators in Hong Kong urged President Donald Trump to “liberate” the semiautonomous Chinese territory during a peaceful march to the U.S. Consulate on Sunday, but violence broke out later in the business and retail district as police fired tear gas after protesters vandalized subway stations, set fires and blocked traffic. (Photo by Kin Cheung/AP Photo)

January 22, 2017; Atlanta, GA, USA; Atlanta Falcons cheerleaders take a picture in the confetti after the game against the Green Bay Packers in the 2017 NFC Championship Game at the Georgia Dome. Atlanta defeated Green Bay 44-21. (Photo by Jason Getz/USA TODAY Sports)

A woman walks up the steps decorated ahead of the Chinese New Year festival in Beijing, China, Thursday, January 12, 2017. The Chinese Lunar New Year is the most important holiday for Chinese and hundreds of millions are expected to return to their hometown to spend the new year with their family and relatives. (Photo by Ng Han Guan/AP Photo)