第6题: [单项选择]Regarded as a kind of art form, toys ______ A. follow a direct line of ascent B. also appeal greatly to adults C. are not characterized by technological progress D. reflect tile pace of social progress 参考答案:C 答案解析:根据最后一段第一句"they (toys) have not been subject to echnological leaps that characterize inventions for a