高等继续教育 / 电子商务英语
正确率：100%
题型描述: 单选题
＿＿＿＿＿＿a teacher, one must first be a pupil.
A.To be
B.Being
C.To have been
D.Having been
＿＿＿＿＿＿a teacher, one must first be a pupil.
A.To be
B.Being
C.To have been
D.Having been
参考答案：
佳题速递：