微型计算机中，控制器的基本功能是______。
A．实现算术运算和逻辑运算
B．存储各种控制信息
C．保持各种控制状态
D．控制机器各个部件协调一致地工作
参考答案：D
解析： 控制器主要由指令寄存器、译码器、程序计数器和操作控制器等部件组成。它是计算机的神经中枢和指挥中心，负责从存储器中读取程序指令并进行分析，然后按时间的先后J顷序向计算机的各部件发出相应的控制信号，以协调和控制机器各个部件协调一致地工作。
Mr. and Mrs. Green were very worried about their son, Leo. He seemed to be dumb (哑的) 51 he was normal in every other way. Mr. and Mrs. Green tried everything to get him to 52 , but with no success. When Leo was six years old, the best doctors in the town 53 him carefully, but could find nothing wrong. And he seemed to be smart. It was just that he 54 spoke. "There might be something wrong with his 55 , and he doesn't know he's able to speak," one doctor said. "But he can read and write," said Mr. Green. "We've written him notes, telling him that he can speak." "It's certainly very 56 ," another doctor said. "Perhaps he'll be able to speak some day." 57 passed. Leo went to university. But he did not speak a 58 word. Then one day, Leo was having a meal with his parents. Without any warning, he looked up from his 59 and said, "Pass me the salt, please." Mr. and Mrs. Green were excited. "You spoke! You spoke!" they cried, "Why have you 60 so long to speak?" "I didn't have anything to say," he said. "Until now everything was perfect. But you forgot to put salt in these potatoes."
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