短文改错。
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（从十一处起）不计分。
Dear sir,
I'm glad to recommend (推荐) you to my friend Li Ming. Li Ming was born in July 15 , 1974 in Beijing. He graduated from Xisi Primary School in 1986 .
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 excellent work, he get a doctor's degree in physics in this year. He is now in good health but would like to make contributions to our
country．I will be most gratefully if you consider my recommendation．Looking forward to receive your
early reply
Yours truly,
Wang Lin