题目内容：

此题要求改正所给短文中的错误。文中共有10处语言错误，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：在缺词处加一个漏词符号（/\）,并在该句下面写出该加的词。

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。

The day before yesterday, my classmates and me went to the park near my school. Can you guess that what we did there? Not for amusement but to take part in a volunteer task. They reached the park at nine o'clock. The whole class divided into three groups. Group One planted trees and water flowers. Group Two picked up litter leaving by the tourists and cleaned all the benches. The group which I was in wiped all the equipments in the Children's Playground. All of us worked hardly. Before noon we finished working. Each of us fell a little bit tired, so we were

happy because we had done a good deed.