American education currently adopts the monorail system. The monorail school system is relative to the double-track school system. Dual-track school system: a top-down structure-universities (later including other institutions of higher learning) and middle schools (including preparatory classes for middle schools); Another bottom-up structure-primary school (later primary school, middle school) and its subsequent vocational schools (first primary vocational education connected with primary school, then secondary vocational education connected with junior high school). The monorail school system has only one structure, either top-down or bottom-up. Monorail school system is a national school system that does not artificially distinguish between academic and vocational preparation.