The purpose of structure diagrams is to show the static structure of the system being modeled. 结构图的目的是显示建模系统的静态结构。
Those vehicles featured an approach known as the two-mode system, which G.M. engineers downsized from bus duty to fit in the smaller trucks. 通用汽车的工程师将原本适用于巴士的混合动力系统缩减后用于小型卡车，即所谓的双模系统。
