PVC(永久虚拟电路)
perpetual virtual circuit
Shell永久变形理论
Shell permanent deformation theory
半永久[性]低压
semi-permanent depression
semi-permanent low
半永久[性]反气旋
semi-permanent anticyclone
半永久储存构架
semipermanent storage structures
半永久电子储存器
semipermanent electronic storage
半永久连接
half - permanent connection
semi-permanent connection
半永久型保温冒口
semi-permanent insulating riser sleeves