一、选择题。(共90题,分为1分题和2分题,满分120分。除标注2分题外,其它均为1分题。）

(81) The type of testing done during software implementation and beforemodule integration is called ____.  
A) unit testing      B) beta testing  
C) system testing D) acceptance testing  

(82) Which of the following is (are) true about software portability? ____.  
I. Using a high-level language that conforms to an ISO standardguarantees portability   across the range of machines that support the language.  
II. Portability is guaranteed across all machines that have the same instruction set and operating system. (2分)  
A) Neither  B) Ⅰ only   C) Ⅱ only   D) Ⅰ and Ⅱ  

(83) A memory-memory, machine instruction for a certain machine has the following format.  
(Such an instruction is similar to a register-register instruction  
except that the operands are displaced addresses in memory.)  
opcode meml displ1 mem2 displ2  
Which of the following could be an assembly lanuage instruction that would be translated into a memory-to-memory instruction for this machine? ____.  
A) ADD 10(R1), 20(R2) B) ADD(10R1), (20R2)  
C) ADD R1, 10(R2), 20 D) ADD R1, 10, 20(R2)  

(84) In a certain cache system, the modified cache block is written to main memory only when the block is replaced. All of the following are used to describe this policy EXCEPT____.   
A) store-in B) write-back C) copy-back D) write-through  

(85) When an amount of memory is requested that is less than the size of a page, but a full page is allocated, the r  esulting waste of memory is called ____.  
A) external fragmentation B) internal fragmentation  
C) inaccessible page faults D) inaccessible garbage  

(86) The time that the CPU spends on a given program can be computed using all of the following expressions EXCEPT ____. (2分)  
A) (CPU clock cycles for the program)*(clock cycle time)  
　   B) CPU clock cycles for the program  
clock rate  
C) (Instruction count)*CPI  
clock rate  
D) (CPU clock cycles for the program)*CPI  
clock rate  

(87) The methods used in Asynchronous Transfer Mode (ATM) are switch technology and which of the following is used to describe this mode?____.   
A) cell exchange          B) packet exchange  
C) message exchange D) information exchange  

(88) In a data communication system, the transport media with the widest frequency band and best reliability is the ____.  
A) telephone line B) coaxial cable  
C) radio channel D) fiber optic cable  

(89) Which of the following statements about the Internet is (are) true?____.　 I. It is possible to have multiple names corresponding to the same IP address.  II. All host names must be registered with an Internet-wide central registry.  
A) Neither B) Ⅰ only C) Ⅱ only D) Ⅰ and Ⅱ  

(90) According to the principle of CRC calculation, given a frame-bit series M =11100111 and the multiple-term formula, frame-bit series generated by the CRC G =110011, then the CRC is ____.(2分)  
A) 111101 B) 00011 C) 11010011 D) 1101001