2017年全国计算机等级考试四级笔试试题及答案52017-06-05 17:41 来源：网络综合
(61) If file A has the capability of 724,the same group’s users of file A may do____．
A) read A only B) write A C) execute A D) non-operation
(62) In which phase of the software engineering process is the Software Requirements Specification developed?____．
A) definition phase B) engineering
C) maintenance D) development phase
(63) The prototyping method is a dynamic design process,which requires people who use prototyping method to have the following capability of____．
A) proficient program expertise B) immediately acquire requirement
C) coordinate & organize eloquently D) handle tools smartly
(64) For relation R where primary key contains multiple attributes,no non-key attribute should be functionally dependent on a part of the primary key. This relation R is at least in____．
A) 1NF B) 2NF C) 3NF D) BCNF
(65) Which of the following statements about object oriented databse is not correct?____．
A) Each object has a unique object identity in the system.
B) Encapsulation and inheritance are two important features of object oriented database.
C) A subclass can inherit the attributes and methods of all its superclasses.
D) A subclass includes the attributes and methods of all its subclasses.
(66) Local bus can increase the data throughput. The bus that is most frequently used is____．
A) VESA B) EISA C) MCA D) PCI
(67) Most frequently used algorithm f or page replacement is____．
A) LRU B) FIFO C) OPT D) PPT
(68) The following three concepts are essential to the OSI model:service,interface and____．
A) networks B) applications
C) protocols D) layers
(69) LANs can be connected by using bridges,which operate in the____．
A) physical layer B) data link layer
C) network layer D) transport layer
(70) TCP service is obtained by having both the sender and the receiver create end points,which are called____．
A) network address B）supernet address
C) socket D) IP address