To the joy of the parents，their only son is now ________ to achieve his goal.[ ]

A．making every effort    

B．making all effort

C．make an effort    

D．sparing no efforts

相比而言车辆发动机润滑油哪种价格钱高。（）

A.矿物润滑油

B.半合成润滑油

C.全合成润滑油

D.都一样