题目内容：

短文改错

假段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。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(＼)划掉。

修改：在错的词下画一横线，并在该词下面写出修改后的词。

Today we had a chemistry test. I found the test difficulty, but I tried hardly to do it. Suddenly Mary, my best friend, asking me to let her to copy my answers. After think for some time, I let her copy my answers. But after the test, all of us were called to the teacher's office. The teacher was angry because we had same answers in the tests. We were warned not to cheat again so she would need to see our parents. I was very upset. I didn't cheat. I was just helping a friend. Why does she punish me?