78.什麼是動能？ (A)物體基於其引力所擁有的能量 (The energy an object has based on its gravitational pull.) (B)物體能夠對化學反應貢獻的能量 (The energy an object could contribute to a chemical reaction.) (C)物體基於其運動所擁有的能量 (The energy an object has based on its motion.) (D)物體基於其溫度所擁有的能量 (The energy an object has based on its temperature.)。