An embedded operating system is the (71) program that manages all the other programs in an embedded device after initial load of programs by a(an) (72). It normally guarantees a certain capability within a specified (73) size and (74) constraint as well as with application programs. It also normally has small foot print including initial boot loader, OS kernel, required device drivers, (75) for the user data and so forth. It has very-likely structure of a normal operating system however mainly differentiated by some factors such as type of pre-installed device, functional limits, taking designed job only.

A．hardware

B．business

C．software

D．external

根据动画中的车刀移动轨迹，为了实现刀尖半径补偿，相应的G代码应该取（）

A.外圆加工用G42，内孔加工取G41

B.外圆加工用G42，内孔加工取G42

C.外圆加工用G41，内孔加工取G41

D.外圆加工用G41，内孔加工取G42