单选题 Any decline in the number of game birds was due to______habitat, over-grazing and th loss of heather moorland.
【正确答案】 A
【答案解析】解析：句意：任何猎禽数量的减少都要归因于栖息地的恶化，过度放牧和石南沼泽地的减少。deteriorate退化，恶化。分析句法结构，此处动词过去分词表示被动完成。