What would have happened ________, a 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 have happened＿＿＿＿, as far as the river bank?

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

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

What would have happened ______,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 have happened＿＿＿＿, as far as the river bank?

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

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

What would have happened,        as far as the river bank?

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

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