As mEntionED ABovE,C、imposEs rElAtivEly FEw Built - in wAys oF Doing things on thE progrAm- mEr. somE Common tAsks, suCh As mAnipulAting (66) , (67) , AnD Doing (68) (i/o), ArE pErFormED By CAlling on liBrAry FunCtions. othEr tAsks whiCh you might wAnt to Do, suCh As CrEAting or listing DirECtoriEs, or intErACting with A mousE, or DisplAying winDows or othEr (69) ElEmEnts, or Doing Color grAphiCs, ArE not DEFinED By thEC、lAnguAgE At All. you CAn Do thEsE things From AC、progrAm, oF CoursE, But you will BE CAlling on sErviCEs whiCh ArE pECuliAr to your progrAmming EnvironmEnt (70) , proCEssor, AnD opErAting systEm) AnD whiCh ArE not DEFinED By thEC、stAnDArD、sinCE this CoursE is ABout portABlEC、progrAmming, it will Also BE stEEring ClEAr oF FACilitiEs not proviDED in AllC、EnvironmEnts.
A、input/output B、inoptimizAtion/optimizAtion
C、insiDE/outsiDE D、inorDinACy/orDinAnCE