题目

阅读理解 Glacier Bay is one of the most famous parks in America, located in the state of Alaska. This park in the southeastern part of the state covers more than 1 million hectares of Alaskan wilderness. It includes mountains, glaciers (冰川), bays, and even rainforests. Glacier Bay supports hundreds of kinds of animals, including many species of birds, fish, bears, whales and sea lions. As its name suggests, much of Glacier Bay National Park is covered by glaciers. A glacier is a large area of ice that moves slowly down a slope (斜坡) or valley, or over a wide area of land. Glaciers c资料分析：据报道，2007年6月下旬以来，栖息在洞庭湖区400多万亩湖中的约20亿只东方田鼠，随着水位上涨部分内迁．它们四处打洞，侵入稻田和村庄，啃食庄稼，严重威胁湖南省沅江市等22个县市区沿湖防洪大堤和近800万亩稻田．蛇是鼠的天敌，每条蛇一年可吃掉约400只田鼠．但是据湖南省野生动植物保护协会统计，长沙市每天大概消费1万千克蛇．这些蛇至少有三成是野生．湖南是产蛇大省，长沙是消费蛇最大的城市．洞庭湖国家级自然保护区如今也是东方田鼠肆虐成灾．但保护区管理局负责人说：“管理局不赞成用化学药物灭鼠．”请根据上述资料回答问题：（1）东方田鼠在分类上所属的门、亚门、纲：______．（2）田鼠“四处打洞”、“啃食庄稼”，这些行为都属于______行为．（3）请写出上述资料中的食物链______．（4）为什么保护区管理局“不赞成用化学药物灭鼠”？______．