<prompt> Nyorai kuenderera mberi kweiyi ndima - Margretta Gretta Kok akazvarwa 16 Gumiguru 1944, muAmsterdam mutambi wechiDutch akasiya basa uyo akapinda mumakwikwi eOlympic a1960 na1964. Muna 1960, akanga ari wechishanu mumakwikwi e200m breaststroke, asi muna 1964 haana kusvika kumagumo. Muna 1966, akahwina menduru yegoridhe mu4 × 100 m medley relay paEuropean Aquatics Championships  <response>: . Munununa wake, Ada Kok, akanga ariwo mutambi wenhangemutange yeOlympic uye aivawo muchikwata chimwe chete ichocho chakahwina menduru yegoridhe mu 1966. 