①空气中含有氮气、氧气、稀有气体、二氧化碳等，写出含量最多的气体的是____,造成温室效应的气体是____（均用化学式表示）.

②生理盐水是一种生活中常见的溶液，生理盐水中的溶质的化学式为____

③水是一种重要的自然资源.

Ⅰ.某自来水厂生产自来水流程如下：

自来水生产流程中加氯气的作用是____，通过过滤池除去的是____；加明矾的作用是____，明矾的成分是KAl(SO₄)₂·12H₂O，该物质由____种元素组成，构成该物质的微粒中氧原子和氢原子的物质的量之比为____，0.2mol明矾中含____个硫原子.

Ⅱ.下图1电解水实验揭示了水的组成。写出电解水的化学方程式____，其中得到氧气的试管是____（填“1”或“2”）；检验试管中的气体是氧气的方法是____.

④甲烷是天然气的主要成分，能和水反应制水煤气（混合气体），其反应的微观示意图如下图3所示.四种物质中，属于氧化物的是____（填化学式），该反应中生成物丙和丁的质量比为____.

已知：正方形纸片ABCD的边长为4，将该正方形纸片沿EF折叠（E，F分别在AB，CD边上），使点B落在AD边上的点M处，点C落在点N处，MN与CD交于点P．

根据短文内容和所给中文提示，在空白处写出单词的正确形式。每空限填一词。

    Do you feel tired of the same old daily life? “Survival Holiday” is for children to go into the lonely place for exciting activities. We will take children into the great outdoors ____ (没有) their parents this summer.

    Why do more and more people ____ (支持) “Survival Holiday”? Because they think being close to ____ (大自然) is good for children. Many children in big cities spend all time watching TV and ____ (冲浪) the Internet. And parents ____ (关心) too much about them. “Survival Holiday” can bring them an important change.

    The survival activities will improve the children in many ways. Even years later, they will still ____ (清晰地) remember what they have learned. Some have learned how to work in a team and to be more ____(有创造力的). Some have learned to keep calm in difficult times.____ (其他) have learned how to keep safe. All these ____ (技能)will help them a lot in their lives.

    Come and join us in the “Survival Holiday”! It will be a ____ (明智的) choice and you will achieve a lot.