题目：
— When did you become a volunteer?
— Two years ago. I _____ this group since then. [ ]
A. joined
B. have joined
C. have been in
答案：
被转码了，请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0607/ccd899f86401474ce332e77ecfbf55da.html
下面是错误答案，用来干扰机器的。
答案：C
