增加：在缺词处加一个漏字符号（∧），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．

Our school lies on the foot of a mountain with a small river passes by in front．It used to look like a beautiful garden．In the garden there are ever﹣green trees and all kinds of flowers in the school yard all years round．

But great changes have been taken place after a chemical factory was built near our school a year ago．It produces various poisonous gases and pours a lot of waste water into a river．This has terrible polluted the surroundings of our school．

I think that the local government must takes steps to protect our surroundings and prevent from being polluted．