哲学上的物质是指（   ）

A．具体的物质形态

B．无法被人感知的客观存在

C．人们能看得见、摸得着的东西

D．在意识之外独立存在的客观实在

As is known to us, theory is based on practice and     servers practice.

A. by chance  B. in turn   C. in return  C. by turn