单选题 During the rainy season the Mississippi River may carry away hundreds of acres of valuable top soil from one area and arbitrarily deposit it in another.

【正确答案】 D
【答案解析】arbitrarily随意地，任意地。randomly随便地。subsequently随后地，后来。law— fully守法地，合法地。mercilessly残忍地，无慈悲地。