direct current adjustive system
operating system job control directive
positive-pressure direct-fired pulverizing system
positive list system system
inter-backup system for central control system and district-level dispatch system
Single school system; Single track system; Unitary school system
Single track system; Single school system; Unitary school system
Unitary school system; Single school system; Single track system
7-year system switching to 8-year system
Accounting environment Accounting theoretical system Accounting standards system
administrative management system of villages and towns and educational system
air data system and inertial reference system
apprenticeship system apprentice system
artificial·Respiratory system·Cardiovascular system
automatic fire alarm system [AFA system]
automation system of the power system
bridge transformed from simple-supported system into continuous system