Well, the article is quite good but I think some sentences sound awkward. I think you would want to focus more on the choices of words to make it better. Some points could be listed out in bullet forms. For example:

> At delivery,a child already has all the nerves cell needed.In the first year,it size doubles, and by the time the child is three,all neurons has reached 80% of that of an adult.

Instead of writing it in sentences, you can make some bullet points to enhance readability. These are my opinions. Keep it up the good work.