题目

A Wechat (微信) is an invention ______ can help people talk to friends, share photos, ideas and feeling freely.        A. which     B. who     C. whose      D / 答案：【答案】A  【解析】考查定语从句。 which can help people talk to friends, share photos, ideas and feeling freely是定语从句，修饰先行词invention，而先行词是物，关系代词用which或that。故选A。 数对是下列方程中（           ）的一个解。    A、     B、   C、   D、