Nobody ________ the answer to the question.

1. A.
   known
2. B.
   know
3. C.
   knows
4. D.
   was knowing

[　　]

If she        the answer to the question, she would tell you．

A．knows           B．will know          C．have known          D．knew

– Does ________ know the answer to the question?

– Me．

A． everybody         B． anybody            C． somebody          D． nobody

John knew the answer to the question.（改为否定句）