问题补充：
I sooner but I didn’t know that they were waiting for me.
A. had come
B. was coming
C. would come
D. would have come
答案：
A. had come
B. was coming
C. would come
(答案→)D. would have come
解析：虚拟语气题。情态动词+have done 表示对过去的假设，我不知道他们在等我否则我会早些到的。根据didn’t know可知说的是过去，所以选D。
