Not until the press reported the pollution _________ why the water supply had been cut off.

Not until the press reported the pollution _________ why the water supply had been cut off.

A．people did know                        B．people had known

C．did people know                        D．had people known

Not until the press reported the pollution _________ why the water supply had been cut off.

1. A.
   people did know
2. B.
   people had known
3. C.
   did people know
4. D.
   had people known

 Not until the press reported the pollution _____________ why the water supply had been cut off.

   A. people knew                                  B. people had known    

C. did people know                                D. had people known

 (2011年浙江金华十校联考)Not until the press reported the pollution________why the water supply had been cut off.

A．people did know                   B．people had known

C．had people known                       D．did people know