Visitors wearing face masks to protect against the coronavirus walk through in a doorway at the Temple of Heaven in Beijing, Thursday, Oct. 1, 2020. Millions of Chinese tourists usually would use their week-long National Day holidays to travel abroad. This year, travel restrictions due to the coronavirus pandemic mean that some 600 million tourists - about 40% of the population - will travel within China during the holiday that began Thursday, according to Ctrip, China's largest online travel agency. (AP Photo/Mark Schiefelbein)