题目

在硫酸工业中，通过下列反应使SO2转化为SO3：2SO2（g）+O2（g）2SO3（g）；ΔH=－196.6 kJ·mol－1。已知常压下平衡混合气体中SO3体积分数为91%，试回答下列问题：（1）在生产中常用过量的空气是为了__________________________________________。（2）加热到400～500 ℃是由于______________________________________________。（3）压强采用__________，原因是_____________________________________________。（4）尾气中的SO2必须回收，是为了_________________________________________。短文改错假定英语课上老师要求同桌之间交换修改作文, 请你修改你同桌写的以下作文。文中共有10处错误, 每句中最多有两处。错误涉及一个单词的增加、删除或修改。增加: 在缺词处加一个漏字符号（）, 并在其下面写出改加的词。删除：把多余的词用斜线（＼）划掉。修改：在错的词下划一横线，并在改词下面写出修改后的词。注意：1. 每处错误及其修改均仅限一词；2. 只允许修改10处，多者（从第11处起）不计分。In the summer holiday, we travelled to Qingdao and paid a visit my uncle there. It’s a tired and boring journey. But the moment I arrived, I fallen in love with the city. It’s so a beautiful city that I can hardly find any word to describe it. The streets are cleaned and the sky is blue. If you walk along the coast, you can feel the wind blow on your face. The sea is vast and sometimes you can find a boat or a ship. You may also do some fishing as possible as it is permit. However, I think the drivers there driving too fast in the street. Your can never be too carefully when crossing the street.