短文改错。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： 在缺词处加上一个漏词符号（∧），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。
Our school lies on the foot of a mountain with a small river passes by. It used to be a quiet, clean and
beautiful place for a school. It is a pity which things have changed after a chemical factory was built near
our school one year ago. Every day the factory produces many waste water and some harmful gases. The
terribly pollution is harmful to our health. What's bad, the great noise from the factory had a bad effect on
our activities. As a result, our school is no longer what it used to. Our teachers and students are miserable
beyond the description.
_______________________________________________________________________________________
