假定英语课上英语老师要求同桌之间互相修改作文，请你修改你同桌的以下作文。
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。
删除：把多余的词用斜线（\）划掉。
增加：在缺词处加一个漏字符号（∧），并在该词下面写出该加的词。
修改：在错的词下划一横线，在该词下面写出修改后的词。
注意：1、每处错误及修改均仅限一词。
2、只允许修改10处，多者（从11处起）不计分。
In my hometown there was a river. Many students go and swim there,
so my parents don’t allow me to do that. They consider swimming
dangerous because of I am very thin and weak. They are afraid
they may drown. One afternoon, my friend and I went out to play.
They played in the river happy while I just stood in the bank.
I really wanted to join them. At last, one friend offered to teach
me where to swim. After half hour, to my surprise, I could swim.
I was exciting.