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：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。

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。

    Yesterday we took part a tree planting activity organised by our class. Early-in the morning, we set out for Bantou Reservoir in Xiamen. When we were arrived there, we began to work immediately. Firstly, we dug holes that are slightly larger than the root balls. Next, we gentle placed the trees into our new homes. After that, we refilled the holes use enough soil to support the root. Finally, we watered the trees. Three hours passed by after we knew it. Tired as we were, we felt exciting, talking and laughing all the way home. How an unforgettable experience!