问题
选择题
A Wechat (微信) is an invention __________ can help people talk to friends, share photo, ideas and feelings freely.
A．which
B．who
C．whose
D．/
答案
答案：A
题目分析：句意：微信是可以帮助人们和朋友自由地聊天，分享照片，想法和感觉。这是一个定语从句，先行词是物invention，关系词可以用which或者that，但是先行词在从句做主语，that不可以省略。故选A。