[填空题]

Passage Two
How does it happen that children learn their mother tongue
so well When we compare with adults learning a foreign 11.______
language, we often find this interesting fact. A little child
without knowledge or experience often succeeds to a complete 12.______
master of the language. A grown-up person with fully developed 13.______
mental powers, in most cases, may end up in a faulty and inex- 14.______
act command. What accounts of this difference 15.______
Despite other explanations, the real answer in my opinion
lies partly with the child himself, partly in the behavior of the 16.______
people surround him. In the first place, the time of learning the 17.______
mother tongue is the most favorably of all, namely, the first 18.______
years of life. A child hears it speak from morning till night and, 19.______
what is more important, always in its genui