A. to encourage people to recycle their rubbish B. to introduce a recycling system for high rises C. to describe the use of computer technology in recycling D. to explain the need for rubbish collection in high rises 参考答案:B 答案解析:[分析] 第一段说明Shantzis系统的好处,第二段说明其构造,第三段说明其操作,第四段说明它在分类回收中的特殊作用,因此文章是在介绍一种新的回收系统。