Passage 1 Is language , like food , a basic human need？ Judging from the drastic experiment of Frederick II in the 13th century , it may be. Hoping to discover what language a child would speak if he

11. Frederick n' s experiment was "drastic" because ()

A. he wanted to prove children are born with ability to speak

B. he ignored the importance of mothering to the infant

c. he was unkind to the nurses and the children

D. he wanted his nurses to say no mother tongue

12. The reason some children are backward in speaking today is that ().

A. they do not listen carefully to their mothers

B. their brains have to absorb too much language at once

C. their mothers do not respond to their attempts to speak

D. their mothers are not intelligent enough to help them

13. By "critical times" the author means ().

A. difficult periods in the child' s life

B. moments when the child becomes critical towards its mother

C. important stages in the child's development

D. times when mothers often neglect their children

14. Which of the following is NOT implied in the passage？ ()

A. The faculty of speech is inborn to man.

B. Children do not need to be encouraged to speak.

C. The child' s brain is highly selective.

D. Most children learn their language in definite stages.

15. If the mother does not respond to her child's signals , the child will().

A. never be able to speak properly

B. stop giving out signals

C. invent a language of its own

D. make little effort to speak