A train with 7000-series railcars stops at a station during an in-service test run in Chicago, the United States, on May 6, 2021. Assembled by China Railway Rolling Stock Corporation (CRRC) Sifang America Incorporated in Chicago, the eight railcars, part of the first batch of the 10 7000-series railcars CRRC Sifang America has delivered to the Chicago Transit Authority (CTA), have officially kicked off in-service test run within CTA traffic system since April 21. (Photo by Joel Lerner/Xinhua)