【正确答案】By productivity, language is designed to make its users form and understand an infinite sentences, most of which are never before produced or heard. For instance, we can write a sentence like the following and go on endlessly: "He bought a book which was written by a teacher who taught in a school which was known for its graduates who...".

【答案解析】[解析] 本题考查语言的定义特点之一——多产性，考生也应掌握语言的任意性、二层性和移位性。