问题补充：
I to my cousin’s birthday party last night, but I was not available
A. went
B. had gone
C. would go
D. would have gone
答案：
A. went
B. had gone
C. would go
(答案→)D. would have gone
解析：句意：昨晚我本来会去参见我的表弟的生日聚会的，但是我没有空。“would+have+done” 表示对过去事情的假设，意思是“本来会做”。结合语境可知选D。
【考点定位】虚拟语气
