识读《三国鼎立形势图》,位于北方的 * * 是
A.西晋
B.魏
C.蜀
D.吴
答案:B
读一读,选一选。
1. Does he like bananas?
A. Yes, he does.
B. No, he doesn't.
2. Does he like pears?
3. Does she like oranges?
A. Yes, she does.
B. No, she doesn't.
4. Does she like apples?
某8088应用系统如图所示,系统中有一片8253,利用通道0输出频率为4KHz的方波,利用通道1完成对外部事件计数,每记满1000个脉冲向CPU申请一次中断,当A15-A3=0000000100100时,地址译码输出为低电平,已知中断类型码为70H。
写出8253控制寄存器的地址(16位地址)。