Good running shoes support the arch of the foot.
好的跑鞋能支撑足弓。
People with flat feet have a very low arch of the foot.
扁平足的人足弓非常低。
几乎没有足弓的脚叫 flat feet(扁平足)。arch support 指支撑该部位的鞋垫或鞋子功能。