题目内容：

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短文。短文中共有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（∧），并在此符号下面写出该加的词。

删除：把多余的词用斜线（＼）划掉。

修改：在错的词下划一横线，并在该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。

When I was a child,I hoped to live in the city.I think I would be happy there.Now I am living in a city,but I miss my home in countryside.There the air is clean or the mountains are green.Unfortunately,on the development of industrialization,the environment has been polluted.Lots of studies have been shown that global warming has already become a very seriously problem.The airs we breathe in is getting dirtier and dirtier.Much rare animals are dying out. We must found ways to protect your environment.If we fail to do so,we’ll live to regret it.