【正确答案】正确答案：Language is a system of arbitrary vocal symbols used for human communication. It is the design features of language that make it unique to human beings. Design features refer to the defining properties of human language that tell the differences between human language and any system of animal communication. They are; ① Arbitrariness; This is a core feature of language, Which means that there is no logical connection between meanings and sounds. There are different levels of arbitrariness; arbitrary relationship between the sound of a morpheme and its meaning; arbitrariness at the syntactic level; arbitrariness and convention.(2 points) ② Duality; It means the property of having two levels of structures, such that units of the primary level are composed of elements of the secondary level and each of the two levels has its own principles of organization. At the lower or basic level there is a structure of sounds, which are meaningless by themselves. But the sounds of language can be grouped and regrouped into a large number of units of meaning, which are found at the higher level of the system. Then the units at the higher level can be arranged and rearranged into an infinite number of sentences.(2 points) ③ Creativity; By creativity we mean language is resourceful because of its duality and its recursiveness. Because of duality the speaker is able to combine the basic linguistic units to form an infinite set of sentences, most of which are never before produced or heard. Language is creative in another sense, that is, its potential to create endless sentences. That is to say, it makes possible the construction and interpretation of new signals by its users.(2 points) ④ Displacement; It means that language can be used to refer to things which are present or not present, real or imagined matters in the past, present, or future, or in far-away places. Displacement benefits human beings by giving them the power to handle generalizations and abstractions. In a word, the intellectual benefits of displacement to us are that it makes it possible for us to talk and think in abstract terms.(2 points) ⑤ Cultural transmission: Language is not biologically transmitted. Instead, it is culturally transmitted from generation to generation through teaching and learning. ⑥Interchangeability: Interchangeability means that any human being can be both a producer and a receiver of messages.

【答案解析】解析：考查人类语言的区别性特征。语言的区别性特征主要包括以下几个方面：任意性、二重性、创造性、移位性，此外还有文化传递性和互换性。