假定英語課上老師要求同桌之間交換修改作文，請你修改同桌寫的作文。文中共有10處語言錯誤，每句中最多有兩處，錯誤涉及一個單詞的增加、刪除或修改。
增加：把缺詞處加一個漏詞符號（∧），并在其下面寫出該加的詞。
刪除：把多余的詞用斜線（\）劃掉。
修改：在錯的詞下劃一橫線，并在該詞下面寫出修改后的詞。
注意：
1.每處錯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）不計分。

    In the past three years，many activities had been organized by our school.What impressed me mostly was an activity called "Learning to Farm".In an autumn afternoon，we went to a farm，where we learned knowledge and had many fun.Having been in the city for such a long time，we were more than happy to go to a countryside.After we arrived，we divided into three groups.Some students learned how to raise chicken，some worked in the garden，and the other helped the farmers with the work in the fishpond.It was not until it was totally dark when we stopped working.Though tired out，but we felt pleased on our way back home.