how long have you -------?
A.borrowed the book B.bought the bike
C.been back D.received the letter
选C 为什么其他的不对
how long have you -------?
A.borrowed the book B.bought the bike
C.been back D.received the letter
选C 为什么其他的不对
how long 是问一个段时间.. 只有C BEEN 是表示时间段的
其他的 .borrowed bought received 时间点发生的动作