kāi tuò
（開辟; 擴展） open up; reclaim; extension; open-out prolongation; baring:
開拓城鄉市場 exploit the urban and rural markets
開拓荒地 reclaim wasteland
開拓市場 develop (explore) markets
為發展石油工業開拓壹條道路 open up a path for the development of oil industry
開拓中美兩國的聯系 start contacts between China and the United States
中國移民在19世紀為開拓美洲大陸作出了貢獻。 Chinese settlers helped tame the American continent during the 19th century.
{礦} （采掘前修建巷道等工序總稱） developing; opening
{數} extension