未知题型
What is the author's attitude in this passage?D.Humorous.
B解析：这是一篇说明文，向读者介绍了几种接收讯息方法的共性和他们各自的特点。explanatory意为'解释性的'。
未知题型 P2P的第二个“P”，指的是（）。
未知题型 听力原文：M: Helen isn't here yet. Did you forget to invite her?W: She was going to come, but then she changed her minD.Why isn't Helen present?A.She decided not to comE.B.She forgot to comE.C.She wasn't inviteD.D.She altered her decision.
未知题型 P2P行业发展迅猛的表现和原因是（）。
