_________for the free tickets,I would not have gone to the films so often.     [ ]

A.  If it is not                                      

B.  Were it not      

C.  Had it not been                                    

D. If they were not

根据成本费用与产量的关系可将总成本费用分解为( )。

A．固定成本

B．可变成本

C．半可变成本

D．生产成本

E．销售成本