短語詞組短語back -up protection system 後備保護(hù)系統(tǒng)redundant back -up system 冗餘後備系統(tǒng)Back -up CollisionIntervention system 及倒車輔助系統(tǒng)a back -up system 輔助設(shè)旎 返回 back-up system