问题 单项选择题

3种类型的通道中支持通道程序并发执行的有( )。

A.字节多路通道

B.数组选择通道

C.数组多路通道

D.3种都是

答案

参考答案:C

解析:[分析] 字节多路通道适用于连接打印机、终端等低速或中速的输入输出设备;数组选择通道适用于连接磁盘、磁带等高速设备,但在一段时间内只能由某台设备独占,通道利用率很低;数组多路通道综合了字节多路通道分时工作和选择通道传输速率高的特点,使得通道既有很高的数据传输率又能获得较高的通道利用率,其实质是对通道程序采用了多道程序设计技术,通道连接的设备可以并行工作。

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Books Information
 Little Bull  Author: Ellen James
Main idea: The book tells us how the lovely 250-pound baby
elephant learns about the world around him
Price: 24.0 yuan
The Trouble with Teachers   Author: Barbara Calamari
Main idea: Angela has found herself in trouble
again at school with her teachers. She and her friends Gina and Johnny will be
  punished.
Price: 15.0 yuan
 I've Got a Secret   Author: Cathy West
Main idea: Nine-year-old Michelle got a new hot-pink notebook
as a birthday gift and she began to keep a diary every day.
Price: 30.0 yuan
Miss Nobody

Author: Tomek Tryzna
Main idea: At the age of fifteen, Marysia moves
with her parents to the nearest big city. Then she meets two girls, Kasia and
 Eva, and
 they begin to teach her the secrets of life.
Price: 33.0 yuan
1. Who is the author of the book Little Bull?
    A. Ellen James.            
    B. Barbara Calamari.    
    C. Cathy West.            
    D. Tomek Tryzna.
2. How much does the book The Trouble with Teachers cost you?
    A. 24.0 yuan.              
    B. 33.0 yuan.          
    C. 30.0 yuan.              
    D. 15.0 yuan.
3. Which book should you buy if you want to know about a kind of animal?
    A. I've Got a Secrets.        
    B. The Trouble with Teachers.  
    C. Little Bull.             
    D. Miss Nobody.
4. Cathy West's book is _____ yuan cheaper than Tomek Tryzna's.
    A. four      
    B. three      
    C.  two      
    D. one
5. Which of the following is TRUE according to the table?
    A. The book with the price of 30.0 yuan tells us how to keep a diary.
    B. Barbara Calamari's book tells us the story in Angela's home.    
    C. Miss Nobody is about a fifteen-year-old girl.
    D. If you pay 20.0 yuan, you can buy two books above.
选择题