2019年全国计算机等级考试四级笔试试题及答案5
(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
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