此题要求改正所给短文中的错误，按下列情况改正：
该行多一个词：把多余的词用斜线（\）划掉；
该行缺一个词：在缺词处加一个漏字符号（∧），在该行下方写上该加的词；
该行错一个词：再错的词下划一横线，在该行下方写出改正后的词。
注意：只需改出10出错误，多者从第11处起不计分。原行没有错的请不要改。
Dear sir,
I am glad to introduce my friend Li Ming to you. Li Ming was born in July 15,1996 in Beijing. He graduated from Xihua primary School in 2007.When he was in the middle school,he did good in maths, physics and chemistry and fond of art. After graduating from No.4 High School, he entered Beijing University study physics. After four year of hard work there, he went to the United States for further study. Because of his good work, he get a degree of Doctor(博士学位）in physics in last year .He is now in good health but would like to make contributions to our country. I will be most grateful if you considered my introduction(介绍）.
Looking forward to receive your early reply!
Yours truly,
Wang Lin.
