单选题
The island where these rare birds nest has been declared a ______.
【正确答案】
D
【答案解析】[解析] conservation“保存(自然资源等)”，the conservation of soft and water“水土保持”；the law of conservation of energy“能量守恒定律”；observation“观察”；reservation“(旅馆房间、戏院座位等的)预订；保留(意见)”；preservation“保存，保护，保持”。