Du Kun,a Chinese boy is called"the youngest writer in the world."He has written three books till now.Du Kun was born in Jiangsu in 1994.When he was 7 months old.his parents started working in over 30 different cities,such as xi'an and Shenzhen.This kind of life gave him things to think and write about.When he was 9 months old,he could speak and at the age of one,he could say five to six hundred words.At three,he could look up words in the dictionary.At four,his father taught him how to learn by himself.His parents like reading very much.So does he.At the age of 5,he began writing fairy tales.At the age of 6.he wrote a novel about his life in different cities with his parents.His fairy tales are all from his life.One day,he found many mice in the house.They not only ate their food but also hurt his mother's hand.So he thought,"If we give mice the stomach of cows,they will eat grass and they will be helpful to people."This was his first fairy tales Change Stomach for Mice.Now he studies well in a middle school. He has written his third book.The novel called Eyes of Children.He says," _ ,I just wrote several books." Du Kun began to use a dictionary,  _  .
when he wrote fairy tales before his father taught him how to learn something after he went to school after his mother taught him how to learn something
Question: Du Kun,a Chinese boy is called"the youngest writer in the world."He has written three books till now.Du Kun was born in Jiangsu in 1994.When he was 7 months old.his parents started working in over 30 different cities,such as xi'an and Shenzhen.This kind of life gave him things to think and write about.When he was 9 months old,he could speak and at the age of one,he could say five to six hundred words.At three,he could look up words in the dictionary.At four,his father taught him how to learn by himself.His parents like reading very much.So does he.At the age of 5,he began writing fairy tales.At the age of 6.he wrote a novel about his life in different cities with his parents.His fairy tales are all from his life.One day,he found many mice in the house.They not only ate their food but also hurt his mother's hand.So he thought,"If we give mice the stomach of cows,they will eat grass and they will be helpful to people."This was his first fairy tales Change Stomach for Mice.Now he studies well in a middle school. He has written his third book.The novel called Eyes of Children.He says," _ ,I just wrote several books." Du Kun began to use a dictionary,  _  .
A. when he wrote fairy tales
B. before his father taught him how to learn something
C. after he went to school
D. after his mother taught him how to learn something
Answer: