It's ashamed of him to have got so much help from others but give         to the society inreturn.[ ]

A. no one    

B. none

C. much

D. a little

销售毛利率是( )。

A．是毛利占销售收入的百分比

B．反映1元销售收入带来的净利润

C．是毛利与销售净利的百分比

D．是销售收入与成本之差