问题
—Why do you look so worried?—My computer broke down and my essay ________ unfinished since.[ ]
A: had left
B: has IMG style="WIDTH: 1px; HEIGHT: 1px; VERTI
C: was left
D: has been left
B: has IMG style="WIDTH: 1px; HEIGHT: 1px; VERTI
C: was left
D: has been left
正确答案是：
