假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。
增加：在此处加一个漏字符号（∧），并在下面写出增加的词；
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11处起）不计分。
Time flies! This is a third year that I have been in this school. In the past two and a half years, our school had organized many activities. What impressed me best was an activity called “Learning to Farm”. In an autumn afternoon, we were sent to a farm which we learned to plant potatoes. Having been in the city for so a long time, we were so happy to go to the countryside. After divided into three groups, we started to work. Some students cut potatoes into pieces; some dug holes, and the others put the pieces of potatoes into the hole, put the earth back and pushed them down hard. We continued doing that until all the work was done. Although we were exhausted, but we felt fulfilled on our way back home.