an hour every day has made a considerable difference to my health.
A. Having walked
B. Walk
C. Walking
D. Walked
网友回答
A. Having walked
B. Walk
(答案→)C. Walking
D. Walked
解析:考查非谓语动词。分析句子结构可知,本句话缺少主语,只有v.ing短语可以作主语,故可排除B、D;且“每天走路一小时”是一种经常性的动作,故排除A。句意:每天步行一小时极大地改善了我的健康(状况)。故C正确。