“ They went to the lecture, but it had been put off.” “ Oh, so they _______.”

“ They went to the lecture, but it had been put off.” “ Oh, so they _______.”

A．needn’t have gone                     B．should have gone

C．mustn’t have gone                     D．don’t need to go

“ They went to the lecture, but it had been put off.” “ Oh, so they _______.”

“ They went to the lecture, but it had been put off.” 

“ Oh, so they _______.”

1. A.
   needn’t have gone
2. B.
   should have gone
3. C.
   mustn’t have gone
4. D.
   don’t need to go

“ They went to the lecture, but it had been put off.” “ Oh, so they _______.”

A. needn’t have gone                        B. should have gone

C. mustn’t have gone                        D. don’t need to go