增加：在缺詞處加一個(gè)漏字符號(hào)（∧），并在其下面寫(xiě)出該加的詞．

刪除：把多余的詞用斜線（\）劃掉．

修改：在錯(cuò)的詞下劃一橫線，并在該詞下面寫(xiě)出修改后的詞．

注意：1．每處錯(cuò)誤及其修改均僅限一詞；

2．只允許修改10處，多者（從第11處起）不計(jì)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．