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    A bag is useful and the word "bag" is useful, too. Here is an interesting phrase, "to let the cat out of the bag". In meaning it is the same as "to tell the secret". And there is an old interesting story about it. Long ago, when farmers wanted to sell chickens at the market, they would usually throw the chickens in cloth bags. But cats were cheaper than chickens at that time, so many farmers would put cats into the cloth bags but not chickens.

    One day, a woman asked a man for a chicken. The man gave her a cloth bag in which there was a cat. The woman begged to see the chicken. When the man opened the cloth bag, a big black cat ran out. Not a chicken! The man's secret was out and everyone knew it.

    Now when we say someone gives away a secret, we say "he lets the cat out of the bag". And that is the story where the interesting phrase came from.

【环境保护】阅读材料，完成下列问题。

    金枪鱼属于热带﹣亚热带大洋性鱼，是洄游鱼类，能作跨洋环游，被称为“没有国界的鱼类”。分布于中低纬度海区，大多数金枪鱼栖息在大陆架海域的深处，它的产卵期很长，产卵海域广，繁殖力旺盛。作为一种营养、健康的现代食品备受推崇，它愈来愈被欧美等发达国家所青睐。今年来，它们的种群数量受到了越来越多的威胁。

分析金枪鱼的种群数量受到威胁的原因及解决措施。

凯旋门所在的城市是（    ）

在1 100℃，一定容积的密闭容器中发生反应：FeO（s）+CO（g）  Fe（s）+CO₂（g）△H=a kJ/mol（a>0），该温度下K=0.263，下列有关该反应的说法正确的是   （   ）