The sport's rules require that a race walker's knees stay straight through most of the leg swing and one foot remain in contact with the ground at all times.
这项运动的规则要求竞走运动员的膝盖在大部分的腿部摆动过程中保持笔直，一只脚始终与地面保持接触。
2
If you follow my three Supplefeet rules for foot care - scrub, moisturise and be shoe-savvy, you should have happy feet for life.
如果你听从我的三个关于足部保健的方法——清洗、滋润和选择合适的鞋子，你将会有一双快乐舒适的脚。
3
If you go by bike or on foot, you must know the traffic rules.