Please answer the following question: Read the following article and select the best answer. Article: We each have a memory . That's why we can still remember things after a long time. Some people have very good memories and they can easily learn many things by heart, but some people can only remember things when they say or do them again and again. Many of the great men of the world have got surprising memories. A good memory is a great help in learning a language. Everybody learns his mother language when he is a small child. He hears the sounds, remembers them and then he learns to speak. Some children are living with their parents in foreign countries. They can learn two languages as easily as one because they hear, remember and speak two languages every day. In school it is not so easy to learn a foreign language because the pupils have so little time for it, and they are busy with other subjects, too. But your memory will become better and better when you do more and more exercises. ,. Question: Everybody learns his mother language _ . - at the age of six - when he is a small child - after he goes to school - when he can read and write
A:
when he is a small child