What ______ had Bob walked farther, as far as the river bank?

   A. would happen       B.could happen        C. would have happened    D.needn’t have happened

What ______ had Bob walked farther, as far as the river bank?

What would happen _____, as far as the river bank?

  A. Bob had walked farther                                      B. if Bob should walk farther

  C. had Bob walked farther                                        D. if Bob walked farther

What would happen _____, as far as the river bank?

 A.Bob had walked farther                  B. if Bob should walk farther

  C. had Bob walked farther                            D. if Bob walked farther