We the difficulty together, but why didn’t you tell me?
A. should face
B. might face
C. could have faced
D. must have faced
网友回答
A. should face
B. might face
(答案→)C. could have faced
D. must have faced
解析：虚拟语气考点，对过去的虚拟，本能……。根据下文的didn’t说明是对过去情况的说明，使用“情态动词+have done”；could have done本可以做某事，实际上却未做；must have done一定做了某事（是对过去所发生情况的有把握的肯定推测）；句意：我们本可以一起面对困难，但是你为什么不告诉我？故C正确。