对于8259A的中断请求寄存器IRR，当某一个IRi端呈现 ______ 时，则表示该端有中断请求。
参考答案：高电平
Everyone was silent as the organizer ________ the result of the speech competition.
A．announced
B．pronounced
C．arranged
D．instructed
铅套管电缆直通头接续时，1x4电缆甲端电缆外护套到已端电缆外护套距离是（）。
A.430mm
B.440mm
C.450mm
D.460mm
