A.系統(tǒng)軟件和非系統(tǒng)軟件; B.應(yīng)用軟件和非應(yīng)用軟件; C.系統(tǒng)軟件和應(yīng)用軟件; D.系統(tǒng)軟件和管理軟件。
A.250mm B.300mm C.350mm D.400mm
A.2m,3m B.2.5m,3.5m C.3m,4m D.3.5m,4.5m