— Why did the dinner party start so late last night?

— It was _____ that caused him to serve dinner an hour later than usual. 

A. we were late   B. we being late          C. our being late    D. because we were late  

— Why did the dinner party start so late last night?

— It was _____ that caused him to serve dinner an hour later than usual. 

A. we were late              B. we being late         C. our being late         D. because we were late  

— Why did the dinner party start so late last night?

— It was _____ that caused him to serve dinner an hour later than usual.

1. A.
   we were late
2. B.
   we being late
3. C.
   our being late
4. D.
   because we were late

— Why did the dinner party start so late last night?

— It was _____ that caused him to serve dinner an hour later than usual. 

A．our being late                                            B．we being late

C．we were late                                             D．because we were late