economically developed areas的用法和樣例：
例句
- Aid provided by the state and developed areas to national autonomous areas has promoted their economic development.
國家和經濟發達地區對民族自治地區的支援，促進了民族自治地區的經濟發展。 - Nine-year compulsory education has basically been popularized in large and medium-sized cities and some economically developed regions.
大中城市和部分經濟發達地區已經基本普及了九年義務教育。
