Walking a mile a day is good exercise. A. It is good exercise for walking a mile a day. B. It is good exercise walking a mile a day. C. It is good exercise to walk a mile a day. D. It is Đoạn văn43/60Walking a mile a day is good exercise.It is good exercise for walking a mile a day.It is good exercise walking a mile a day.It is good exercise to walk a mile a day.It is good exercise to walking a mile a day.Giải thíchChọn C