cooperative

a.合作的

cookery, cookery book (also `cookbook), cookhouse, cookie (also cooky), cooking, cool, cool-headed, coolant, cooler, coolie, cooling, cooling tower, cooling-off, coolly, coolness, coon, coop, cooper, cooperate, cooperation, coordinate, coordination, coordinator, coorperation, coot, cop, cop-out, copain, copartner, copartnership, cope, cope with, copeck (also kopeck), Copernican, copier, coping, coping-stone, copious, copiously, copper,