<prompt> Bhala ukuqhubeka kwalesi sigaba - UMargretta Gretta Kok owazalwa ngo-16 Okthoba 1944, e-Amsterdam ungumbhukudi waseDashi osethathe umhlalaphansi owabamba iqhaza kuma-Olimpiki asehlobo ka-1960 no-1964. Ngo-1960, waba ngowesihlanu emncintiswaneni wamamitha angama-200, kanti ngo-1964 akazange afinyelele kowamanqamu. Ngo-1966, wanqoba indondo yegolide emncintiswaneni we-4 × 100 m medley emncintiswaneni we-European Aquatics Championships  <response>: . futhi. Udadewabo omncane, u-Ada Kok, naye wayengumbhukudi wama-Olympic futhi wayeyingxenye yeqembu elifanayo elazuza igolide le-medley ngo-1966. 