参考答案：C

解析：动词辨析。abate(风、暴风雨、声音等)减弱，减轻，降低：The ship sailed when the storm abated．风暴减弱时船开航了。lessen减少，减轻：The pain was already lessening．疼痛正在减轻。pour灌注，倾泻：It was pouring．下倾盆大雨。accumulate积聚，堆积：He accumulated a good library．积累了丰富的藏书。evaporate蒸发，消失：The sun will evaporate the mist．太阳会蒸发雾气。