The various republics and regions that comprised the ussr differed greatly in the standard and quality of life and the level of development (an important issue that became a sore spot during the collapse of the soviet union in 1991). which of the republics listed below were - during the soviet times - predominantly rural, agricultural and industrially under-developed?

central asian republics (tadjikistan, kirgiziya [now kyrgyzstan], uzbekistan)

baltic republics (latvia, lithuania, estonia)

central european republics (i. e. russia)

eastern european countries (poland, bulgaria, etc.)