question: How did the capacitor traditionally used in radio tuning circuits change over time ?
answer: use polymer foil dielectric between the moving and stationary plates
turker_answer: The capacitor traditionally used in radio tuning circuits changed to use polymer foil dielectric between the moving and stationary plates .
rule-based: The capacitor traditionally used in radio tuning circuits change over time by use polymer foil dielectric between the moving and stationary plates .