first-tier cities
【一线城市】
Meanwhile, as the hotpot market in China's first-tier cities — such as Beijing and Shanghai — reaches a saturation point, some brands have chosen to set their sights on third or fourth-tier cities.
与此同时，由于中国一线城市如北京和上海的火锅市场已经达到饱和状态，一些品牌选择将目光投向三线或四线城市。