A（）consists of the symbols, characters, and usage rules that permit people to communicate with computer.

A．programming language

B．network

C．keyboard

D．display

以基期成本费用水平为基础，结合预算期业务量水平及有关影响成本因素的未来变动情况，通过调整有关原有费用项目而编制预算的预算称为( )。

A．零基预算

B．弹性预算

C．静态预算

D．增量预算