From childhood to old age, we all use language as a (1) of broadening the knowledge of ourselves and the world about us. When humans first (2) , they were like newborn children, (3) to use this valuable tool. Yet once language developed, the possibilities for human- kind’s future attainments (成就，造指) and cultural growth increased.
Many linguists believe that evolu- tion is (4) for our ability to produce and use language. They (5) that our highly evolved brain provides us (6) an innate (先天的) language ability not found in lower (7) . Proponents of this innateness theory say that our (8) for language is inborn, but that language itself develops gradually, (9) a function of the growth of the brain during childhood. (10) there are critical biological times for language development.
Current (11) of innateness theory are mixed, however, evidence (12) the existence of some innate abilities is undeniable. Indeed, more and more schools are discovering that foreign languages are best taught in the (13) grades. Young children often can learn several languages by being (14) to them, while s have a much harder time learning another language once the (15) of their first language have become firmly fixed.
Although some aspects of language are (16) innate, language does not develop automatically in a vacuum. Children who have been (17) from other human beings do not possess language. This demonstrates that (18) with other human beings is necessary for proper language development. Some linguists believe that this is even more basic to human language (19) than any innate capacities. These theorists view language as imitative, learned behavior. In other words, children learn language from their parents by (20) them. Parents gradually shape their child’s language skills by positively reinforcing precise imitations and negatively reinforc- ing imprecise ones.