 Complete the following phrase:  Karel Třešňák born February 21, 1949 in Karlovy Vary is a former Czechoslovak slalom canoeist who competed in the 1970s. He won seven medals at the ICF Canoe Slalom World Championships with two golds C-1 team: 1973, 1975 a silver C-1: 1973 and four bronzes C-1: 1977; C-1 team: 