第15题: [单项选择]指令周期是指( )。 A. CPU从主存取出一条指令的时间 B. CPU执行一条指令的时间 C. CPU从主存取出一条指令加上CPU执行这条指令的时间 D. 时钟周期时间 参考答案:C 答案解析:指令周期定义为CPU从主存取出一条指令加上CPU执行这条指令的时间。时钟周期是系统主时钟信号持续一个周期的时间。
第25题: [单项选择]What happened to the man last week A. He met the woman’s friend in the street. B. He heard from their friend. C. He met their friend in the street. D. He telephoned the woman’ s friend. 参考答案:C 答案解析:[解析] M: I came across our friend Michael last week in the street. He said he hadn’ t heard from
