Passengers have smartphone-generated QR codes scanned by ticket machines before entering Futian Station of Shenzhen Metro in Shenzhen, south China's Guangdong Province, May 8, 2018. For most Chinese in the 1970s, one of their dreams was to own "three wheeled things and one vocal thing" which, namely, were a bicycle, a sewing machine, a watch and a radio. By and large, this dream became easily accessible during the 1980s and the 1990s, and "the big four" were replaced by TV set, refrigerator, washing machine and tape recorder. With people's ever-growing needs for a better life along with rapid economic and technological development, decent housing, private car, personal computer and smartphone became part of everyday life. (Xinhua/Mao Siqian)