Complex sentence: The Canadian Grand Prix saw the race was stopped after 64 laps due to the weather so Cevert finish 6th, United States Grand Prix saw Cevert's only win when Stewart's tires began to go off and the gap closed.
Split into simpler sentences: The Canadian Grand Prix saw the race stopped after 64 laps due to the weather and Cevert finished 6th. The United States Grand Prix saw Cevert's only win when Stewart's tyres began to go off and the gap closed.