题目内容：

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。

Dear Sir,

I'm writing to you for the mobile phone which I buy on 20th August 2016 at Attracting Shopping. Ten days after that, it didn't ring or could it send short messages. Then I reported it to the seller, but was told that the model had been selling out and I had to wait at least three month for a new one. Then I wanted it to repaired, but he said since it was a new model, it was impossible to fixing it without the right spare parts. How disappointing I was by hearing that! How can I wait that long? However, I have to write to you and ask you to have the phone replaced within a week or return me back the money.

I'm looking forward to your early reply!

                                                                Sincerely yours

                                                                  Li Hua