下列关于重力的叙述正确的是（　　）

A．重力就是地球对物体的吸引力

B．重力的方向总是垂直向下的

C．自由下落的物体不受重力

D．地球上所有物体所受重力的施力物体都是地球

Activity Based Costing (ABC) is an (126) technique that allows an organization to determine the actual (127) associated with each product and service produced by the organization without regard to the organizational structure. This chapter explains some of the uses and benefits of Activity Based Costing. We use IDEFO (128) modeling in conjunction with ABC to enable more effective business (129) design decisions.
In order to achieve the major goals of business process improvement, process simplification and improvement, FAA managers need to fully understand the cost, time, and quality of activities performed by employees or machines throughout an entire organization. ABC methods enable (130) to cost out measurements to business simplification and process improvement.

A．activity

B．quality

C．cost

D．process