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, 错误涉及一个单词的增加、删减或修改。

增加：在缺词处加一个漏词符号（∧）, 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 Mr. Green，

I'm Li Hua, a student whom you once teach spoken English. Now our school asks me invite you to be a spoken English teacher on the English Summer Camp during the summer holiday. Here is anything about the activity. The camp lasts from July 20 and August 10, 2011. In the morning, you'll give three spoken English classes so you are expecting to prepare different topic to communicate with students. In the afternoon, there're main outside activities such as having some picnics and visit parks and museums, etc. I hope you will accept the invitation even if you have free time.