I don’t know if you noticed their absence or not but we .A. didB. haveC. hadD. were

问题补充：

I don’t know if you noticed their absence or not, but we .

A. did

B. have

C. had

D. were

答案：

(答案→)A. did

B. have

C. had

D. were

解析：but we did 是but we noticed their absence or not的替代式省略。