gravitational condensation system重力单位制

gravitational gliding system重力滑动构造

gravitational sewerage system重力排水系统

gravitational refrigerating system重力循环制冷系统

gravitational condensation system of units重力单位制

inertial-gravitational guidance system惯性重力制导系统

gravitational rainwater drainage system重力流系统

British gravitational system of units英国重力单位制

British gravitational system of unit英国重力单位制