C1 letters or emails, usually advertising products or services, that are sent to people although they have not asked to receive them
mail that advertises products and services and is sent to people although they have not asked to receive it:
advertising material that is sent to homes and businesses without their asking for it:
英语词典包含110679条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。