the young man has been a doctor _______.A.five years agoB.since five years befoeC.for five yearsD.since five years ago B和D有什么根本上的区别吗?C是 for five year .
问题描述：
the young man has been a doctor _______.
A.five years ago
B.since five years befoe
C.for five years
D.since five years ago
B和D有什么根本上的区别吗?
C是 for five year .
答