自动返回参考点指令为（）。
A.G27
B.G28
C.G29
D.G30
参考答案：B
Always remember it is none of your business _____ other people think about you．Just believe in yourself．
A．how
B．what
C．which
D．when
一个MAC地址有（）比特
A.6
B.12
C.24
D.48
