生态系统中的能量最终来自[]A．植物体B．微生物C．动物体D．太阳能-八年级生物

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• 下图为生态系统碳循环示意图，请据图回答下列问题。（1）由图可知，碳在生态系统中主要以_________的形式进行循环。（2）大气中的二氧化碳首先依赖于图中②所代表的_________进入-八年级生物
• 肉类和鸡蛋的价格比粮食和蔬菜高，从生态学的观点看，这是由于[]A．饲养动物麻烦，时间长，投资大B．动物性食品营养价值高C．食物链延长，能量流失多，动物性食品成本高D．栽培植-八年级生物
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• 下图是自然界碳循环的简图，图中甲、乙、丙各代表[]A．生产者、分解者、消费者B．消费者、分解者、生产者C．分解者、生产者、消费者D．生产者、消费者、分解者-八年级生物
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• 在“草→昆虫→食虫鸟→鹰”这条食物链中，全部昆虫消耗的能量比全部狼所消耗的能量[]A．多B．少C．相等D．大约相等-八年级生物
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• 古书《说苑．正谏》中有这样一段记载：“园中有树，其上有蝉，蝉高居悲呜，饮露，不知螳螂在其后也；螳螂委身曲附欲取蝉，而不知黄雀在其傍也；……”这是比喻社会现象的寓言，但却反-八年级生物
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• 小华同学说：“爷爷讲在他小时候，村边的小河里有许多鱼、虾，稻田中有不少黄鳝和泥鳅。现在河里和稻田中几乎没有鱼、虾了。”这是什么原因呢？（1）请对上述情况做出假设：_______-八年级生物
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• 研究生态系统的能量流动，可帮助人们合理地调整生态系统中能量流动的关系，使能量_________地流向对人类最有益的部分。-八年级生物
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• 下图是珠江三角洲的农民充分利用自然条件，建立的该地特有的蔗基鱼塘和桑基鱼塘示意图。请据图回答：（1）这种人工生态系统最基本的生物因素是___________。要使它长期稳定发展-八年级生物
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