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
网友回答
A. Bob had walked farther
B. if Bob should walk farther
C. if Bob walked farther
(答案→)D. had Bob walked farther
解析：考查虚拟语气和倒装句。本句是与过去事实相反的倒装句，故条件句中使用过去完成时的形式，如果把if去掉，句子要使用部分倒装的形式。句意：如果Bob走到河堤边上，会发生什么样的事情呢？故D项正确。