(61)There are several periods in a computer,the shortest period is
A)Instruction period B)Machine period C)Beat period D)CPU period
(62)Which set is empty?
A){x|x is a real number and x2=9
B){x|x is a real number and x2——1=0}
C){x|x is a real number and x21=0}
D){x|x is a real number and x=2x1}
(63)What is the relation represented in the exhibit shown below?
A)R={(1,2),(1,3),(1,4),(1,5)}
B)R={(1,1),(2,2),(3,3),(4,4),(5,5)}
C)R={(1,2),(1,3),(1,4),(2,3),(4,1),(4,5),(5,5)}
D)R={(1,2),(1,3),(1,4),(2,2),(2,3),(4,1),(4,4),(4,5)}
(64)What is the contrapositive of the following implication?
“If it is raining,then I get wet.”
A)If I get wet,then it is raining.
B)If I am wet ,then if is raining.
C)If it is not raining,I do not get wet.
D)If I do not get wet,then it is not raining.
(65)Which property does R posses?
Let A={1,2,3,4}and let R ={〈1,2〉,〈2,2〉,〈3,4〉,〈4,1〉}
A)Symmetry B)Reflexivity C)Asymmetry D)Antisymmetry
(66)When walking a tree,which traversal method yields a prefix,or Polish,form?
A)lnorder B)Preorder C)Postorder D)Reorder
(67)ln the following statements about graph operations,which one isNOT correct?(2 grades)
A)Spanning tree of a graph may not be unique.
B)Minimum spanning tree of a graph may not be unique.
C)Finding critical path is an operation on directed graph.
D)Finding critical path is an operation on undirected graph.
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