第4题: [单项选择]______ is a design feature of human language that enables speakers to talk about a wide range of things, free from barriers caused by separation in time and space. A. Displacement B. Arbitrariness C. Duality D. Productivity 参考答案:D 答案解析:语言的普遍特征(Design features)包括以下几个:语言是任意的(arbitrariness),语言具有双层结构 (duality),语言是多产的(productivity),语言是移位的(