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。文中共有10处语言错误，每句中最多有两处。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(＼)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。

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。

    Mr. Li is my head teacher. He is now in his thirty and has been teaching in almost ten years. He has much knowledges and his teaching method is scientific. All of us enjoy his lessons which are lively and interested. Not only is he strict and also he is kind and patient. As a result, he is popular with our students. All these years he has devoted to teaching his students. In addition, he often gave his encouragement to us, that means a lot to us. With his help, we have made a great progress. We all love him!