Passengers check in at Tianjin Binhai International Airport in Tianjin, north China, Jan. 28, 2021. China kicked off its annual travel rush, known as "chunyun," on Thursday, with hundreds of millions starting to head home for the Spring Festival that falls on Feb. 12 this year. Known as the world's largest annual human migration, the travel rush lasts 40 days from Jan. 28 to March 8 this year. (Xinhua/Li Ran)
