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(Λ)，并在其下面写出该加的词。
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。
Although all the students seem very happily at our school, as far as we concerned, the buildings would be more beautiful if the school could be decorated. We students thought the school looks like a desert and the concrete walls like the grey sky in a rainy day. We would be much happier and are able to study well if the walls of the school could be decorated with posters, photos and paintings, that could certainly broaden our horizons. Original art work are too expensive, but unless we buy art posters, the cost will be low. Using only a little money, it can make our school a nicer place.