下面短文中有10处语言错误，请在有错误的地方增加、删除或修改某个单词。
增加：在缺词处加一个漏词符号（∧），并在其下面写上该加的词。
删除：把多余的词用斜线（﹨）划掉。
修改：在错的词下划一横线，并在该词下面写上修改后的词。
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 participate in a volunteer labour. They reached the park on nine o'clock. The whole class divided into three groups. Group One planted trees and watered flowers. Group Two was told to pick up litter(垃圾) leaving by the tourists and cleaned all the benches. Group Three wiped all the equipments on the Children's Playground. All of us worked hardly. Before noon we finished working. Each of us feel a little bit tired, so we were happy because we had done a good deed.