(1) 用于存放执行指令的地址。若存储器按字节编址且指令长度为1_爱下问搜题

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问题单项选择题

(1) 用于存放执行指令的地址。若存储器按字节编址且指令长度为16位，则程序顺序执行时，每执行一条指令，程序计数器的值增加 (2) 。

(2)

A．1

B．2

C．3

D．4

答案

参考答案：B

解析：在CPU中，程序计数器(PC)是用于存放执行指令的地址的，所以第1空应该选择C。内存地址是按字节(8位)编码的，如果指令的长度为16，则每执行一条指令程序计数器里面的执行指令地址应该增2。

完形填空

Everyone in our class loves sports. Every morning       we get up, we do morning exercises. After the second class, we       exercise again. We only have       classes twice a week, but we do physical training(体育锻炼) at five every      . The most popular       is basketball. The       enjoy playing it and many of the girls like it, too. Another popular sport is soccer and in every class there       a lot of students who like soccer very much. Volleyball is often played when the weather is      . We have school teams in basketball,       and volleyball. Our teams often       friendship matches(友谊赛)with teams from other schools. When there is a match,       of us are very excited to go to watch it.
Besides(除…之外) ball games, some of us like track and field events(田径运动),       we often practice running and others. Every term(学期) we have       in these events and once a year we have a       meeting.
Sports help us to keep       and happy. Do you like sports?

单项选择题

以下哪类分子可以彻底氧化为二氧化碳和水，不产生废物（）

A、脂肪酸

B、氨基酸

C、核酸

D、葡萄糖