[单项选择]Is language, like food, a basic human need without which a child at a critical period of life can be starved and damaged Judging from the drastic experiment of Frederick Ⅱ in the thirteenth century, it may be. Hoping to discover what language a child would speak if he heard no mother tongue, he told the nurses to keep silent.
All the infants died before the first year. But clearly there was more than lack of language here. What was missing was good mothering. Without good mothering, in the first year of life especially, the capacity to survive is seriously affected.
Today no such severe lack exists as that ordered by Frederick. Nevertheless, some children are still backward in speaking. Most often the reason for this is that the mother is insensitive to the signals of the infant, whose brain is programmed to learn language rapidly. If these sensitive periods are neglected, the ideal time for acquiring skills passes and they might never be learned so easily again. A bird
A. to prove that children are born with the ability to speak
B. to discover what language a child would speak without hearing any human speech
C. to find out what role careful nursing would play in teaching a child to speak
D. to prove that a child could be damaged without learning a language