—Why do you look so worried? —My Macbook Pro broke down and my paper unfinished since.A. w

问题补充：

—Why do you look so worried?

—My Macbook Pro broke down and my paper unfinished since.

A. was left

B. has left

C. left

D. has been left

答案：

A. was left

B. has left

C. left

(答案→)D. has been left

解析：考查时态题。我的苹果笔记本坏了，我的论文还没写完呢。根据since可知，本句应用现在完成时。