地球孕育了生命，地球是人类的摇篮，但21世纪地球生态环境问题日益严峻。人类不顾长远和全局利益，为了眼前的经济利益和地方的局部利益破坏性地利用自然：乱砍乱伐导致森林破坏，水土流失；过度耕种放牧导致土地沙化，沙尘肆虐；过度消费加剧空气污染，物种退化。

结合材料运用联系的观点分析生态问题。

    It was Children's Day yesterday, we 1the park. Our teacher was 2us.

    3 many people there. Some Young Pioneers (少先队员)4 near the river.

    5 sang and danced. There were some6 on the river. There was a hill

    7. Some boys8 in the river. We sat under 9 apple tree with our teacher. We 10on Children's Day yesterday.

N₂（g）+O₂（g）═2NO（g）△H=+180kJ•mol^﹣1

则2CO（g）+2NO（g）═N₂（g）+2CO₂（g）的△H是（   ）

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