问题补充:
Alex changed his mind at the last minute,otherwise we an agreement.
A. should have reached
B. could have reached
C. can reach
D. should reach
答案:
A. should have reached
(答案→)B. could have reached
C. can reach
D. should reach
解析:
句意为:亚历克斯最终改变了主意,否则的话我们就会达成一致了。对过去事情的推测,应该使用“情态动词+have done”。should have done应该已经做了……;could have done很可能已经做了……。所以应该选择B项。