We should balance our work and relaxation, and only by doing that, as everybody would agree,

____ a good state of mind. [      ]

A. can we have      

B. we do have    

C. we will have      

D. we must have

后张法中预应力筋承受的张拉力是通过( )传递给混凝土构件的。

A．粘结力

B．摩擦力

C．压力

D．锚具