问题补充：
---May I use your computer, Alex?
---Sorry. Mine .
A. has repaired
B. is being repaired
C. has been repaired
D. is repairing
答案：
A. has repaired
(答案→)B. is being repaired
C. has been repaired
D. is repairing
解析：考查时态及语态。句意：阿历克斯，我可以用你的电脑吗？——抱歉。我的正在维修中。结合语境可知下文描述的是正在进行的动作，用进行时态，主语是动作对象，故用被动语态，选B。
