Why do you look so worried? -- My computer broke down and my essay since.A. has been

问题补充：

-- Why do you look so worried?

-- My computer broke down and my essay since.

A. has been left unfinished

B. has left to finish

C. was left to finish

D. had been left unfinished

答案：

(答案→)A. has been left unfinished

B. has left to finish

C. was left to finish

D. had been left unfinished

解析：考查时态，句意：你为什么看起来如此担心：——我的电脑崩溃了，我的论文后来就一直没有完成。结合句意可知下文描述的是现在已经完成的动作故用完成时态，论文以被遗留的对象故用被动语态。选项BC语义不符，故选A。