一旦语言从2岁左右开始发展，他们就有了一个符号表征系统，可以谈论过去和现在环境之外的事情。
Once language starts to develop from about age 2, they do have a system for symbolic representation and can talk about things which aren't in their immediate environment including the past.
在上世纪六十年代以前，语言的符号表征一直被视为是人类的专利。
Until the 1960s, symbolic representation of language was thought to be uniquely human.
在上世纪六十年代以前，语言的符号表征一直被视为是人类的专利。
Until the 1960s, symbolic representation of language was thought to be uniquely human.
应用推荐