合成氨工业的原料气H₂，可用天然气制取，其生产流程如图：

（1）写出反应I的反应方程式：____ 该反应的平衡常数表达式为：____ 　；

（2）转化炉中反应为：CO（g）+H₂O（g）⇌CO₂（g）+H₂（g），其平衡常数与温度关系如表：

该反应为：　放热　反应（填“吸热”或“放热”）．

（3）合成氨反应原理为：N₂（g）+3H₂（g）⇌2NH₃（g）△H=﹣92.4KJ/mol

回答下列问题：

①工业合成氨原料氮气制备方法是____ 

②在一定温度下，将1molN₂和3molH₂充入一容积不变的密闭容时器中进行合成反应，达到平衡时，容器的压强为起始的$\frac{4}{5}$，平衡状态记为S₀，则平衡时容器内NH₃的体积分数为____ ；若保持温度不变，开始时向容器加入a mol N₂，b mol H₂，c mol NH₃，要使反应始终向逆反应方向进行，且达到平衡后向各物质的理与原平衡S₀完全相同，则起始时c的取值范围应是____ ．

阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处 填入一个适当的词或使用括号中词语的正确形式填空。

If you like candy and chocolate, Candylicious must be the ____ (good) place for you. Candylicious is a store and it is in Singapore. ____ a large store it is! It is about 836 square meters. When you go into Candylicious, you will be ____(surprise) to see too much candy and chocolate. There are over 5,000 kinds of candy and chocolate ____ the store.

The owners of the store have ____ candy stores. One is in Singapore. The other one is in the Dubai Mall. That store is the largest candy store all over the world. ____ aim of the Candylicious is “Eat Happily”. The owners want ____ (make) the world a happier place.

“Come to ____ (we) stores. We make sure they are happy ____ (place) for you. You know, the easiest pleasure (快乐）is from candy,’’ the owners of Candylicious say. Want to go to Candylicious and ____ (enjoyment) the colorful candy and chocolate? Let’s go there together.