Public relations practice is the deliberate , planned and sustained effort to establish and maintain mutual understanding between an organization and its public.

A．complete

B．related

C．intentional

D．active

以下不属于物权法基本原则的是（）

A．物权法定原则 

B．一物一权原则 

C．物权公示原则 

D．责权利相统一原则