We ________ such great achievements without your efforts. Thanks a lot.
A.can’t have made
B.couldn’t have made
C.were unable to make
D.are unable to make
网友回答
B解析这题考查情态动词对过去的虚拟，couldn’t have done“过去不可能做…，而实际上做了”，句意是：没有你的努力，我们不可能取得这么大的进步，（而实际上取得了）。选B。