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.
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。
2
“Of all the techniques, ” Wassmer adds, “simple changes in body language are the most surprising in terms of immediate results.
“在所有的技巧中，”沃斯默补充道，“简单地改变身体语言最能带来令人吃惊的直接结果。
3
This is by far the most interesting element, because it makes the XO-1 an immediate development environment. (Python is an interpreted language.)