13. Essentially, a theory is an abstract, symbolic representation of what is conceived to be reality.
13.理论在本质上是对认识了的现实的一种抽象和符号化的表达。
14. Long before children are able to speak or understand a language, they communicate through facial expressions and by making noises.
14.儿童在能说或能听懂语言之前，很久就会通过面部表情和靠发出噪声来与人交流了。
