下面程序的输出结果是( )。L=[('b', 3), ('c', 1), ('d', 2), ('a', 5)]L.sort()print(L) A: {('a', 5), ('b', 3), ('c', 1), ('d', 2)} B: [('a', 5), ('b', 3), ('c', 1), ('d', 2)] C: [('c', 1), ('d', 2), ('b', 3), ('a', 5)] D: [('b', 3), ('c', 1), ('d', 2), ('a', 5)]
下面程序的输出结果是( )。L=[('b', 3), ('c', 1), ('d', 2), ('a', 5)]L.sort()print(L) A: {('a', 5), ('b', 3), ('c', 1), ('d', 2)} B: [('a', 5), ('b', 3), ('c', 1), ('d', 2)] C: [('c', 1), ('d', 2), ('b', 3), ('a', 5)] D: [('b', 3), ('c', 1), ('d', 2), ('a', 5)]
设a=﹣(﹣2)2,b=﹣(﹣3)3,c=﹣(﹣42),则﹣[a﹣(b﹣c)]= A: 15 B: 7 C: ﹣39 D: 47
设a=﹣(﹣2)2,b=﹣(﹣3)3,c=﹣(﹣42),则﹣[a﹣(b﹣c)]= A: 15 B: 7 C: ﹣39 D: 47
设a=-(-2)2,b=-(-3)3,c=-(-42),则-[a-(b-c)]=( ) A: 15 B: 7 C: -39 D: 47
设a=-(-2)2,b=-(-3)3,c=-(-42),则-[a-(b-c)]=( ) A: 15 B: 7 C: -39 D: 47
下面哪个分数比3/5大?( ) A: 1/2 B: 39/50 C: 7/25 D: 3/10
下面哪个分数比3/5大?( ) A: 1/2 B: 39/50 C: 7/25 D: 3/10
下面哪个是合法的序列化数据格式?() A: O:7:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";s:25;} B: O:7:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";i:25;} C: O:8:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";s:25;} D: O:8:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";i:25;}
下面哪个是合法的序列化数据格式?() A: O:7:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";s:25;} B: O:7:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";i:25;} C: O:8:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";s:25;} D: O:8:"Student":2:{s:4:"name";s:4:"qian";s:3:"age";i:25;}
给定关系R(A,B,C,D)和关系S(C,D,E),对其进行自然连接运算R▷◁s后的属性列为5个;与σR.B>S.E(R▷◁S)等价的关系代数表达式为() A: σ2>7(R×S) B: π1.2.3.4.7(σ’2‘>’7‘^3=5^4=6(R×S)) C: σ’2‘>‘7’(R×S) D: π1.2.3.4.7(σ2>7^3=5^4=6(R×S))
给定关系R(A,B,C,D)和关系S(C,D,E),对其进行自然连接运算R▷◁s后的属性列为5个;与σR.B>S.E(R▷◁S)等价的关系代数表达式为() A: σ2>7(R×S) B: π1.2.3.4.7(σ’2‘>’7‘^3=5^4=6(R×S)) C: σ’2‘>‘7’(R×S) D: π1.2.3.4.7(σ2>7^3=5^4=6(R×S))
写一个文法G,使其语言为不以0开头的偶数集。 A: G[S]:S→AB|BA→AD|CB→2|4|6|8|0C→1|3|5||7|9|B B: G[S]:S→AB|BA→AD|CB→1|2|3|4|5|6|7|8|9C→2|4|6|8|0 C: G[S]:S→AB|BA→AD|CB→2|4|6|8|0C→1|2|3|4|5|6|7|8|9D→0|C D: G[S]:S→AB|BA→AD|DB→2|4|6|8|0D→1|2|3|4|5|6|7|8|9|0
写一个文法G,使其语言为不以0开头的偶数集。 A: G[S]:S→AB|BA→AD|CB→2|4|6|8|0C→1|3|5||7|9|B B: G[S]:S→AB|BA→AD|CB→1|2|3|4|5|6|7|8|9C→2|4|6|8|0 C: G[S]:S→AB|BA→AD|CB→2|4|6|8|0C→1|2|3|4|5|6|7|8|9D→0|C D: G[S]:S→AB|BA→AD|DB→2|4|6|8|0D→1|2|3|4|5|6|7|8|9|0
下列程序段中,循环体s = s +1执行了几次? For i = 0 To 7 Step 3 For j = 0 To 7 Step 2 s = s + 1 Next Next
下列程序段中,循环体s = s +1执行了几次? For i = 0 To 7 Step 3 For j = 0 To 7 Step 2 s = s + 1 Next Next
下列程序段中,循环体s = s +1执行了几次?For i = 0 To 7 Step 3 For j = 0 To 7 Step 2 s = s + 1 NextNext A: 5 B: 7 C: 12 D: 49
下列程序段中,循环体s = s +1执行了几次?For i = 0 To 7 Step 3 For j = 0 To 7 Step 2 s = s + 1 NextNext A: 5 B: 7 C: 12 D: 49
写出下列指令运行结果:A=ones(2,5);A(:)=1:10;s=[2 3 7];A(s)Sa=[10 20 30]A(s)=Sa
写出下列指令运行结果:A=ones(2,5);A(:)=1:10;s=[2 3 7];A(s)Sa=[10 20 30]A(s)=Sa