下列两组织或物质间X线对比度最大的是

A．骨与空气

B．骨与肌肉

C．骨与脂肪

D．肌肉与空气

E．肌肉与脂肪

All of them try to use the power of the workstation（）information in a more effective way.

A. presenting

B. presented

C. being presented

D. to present