能正确表示“当x的取值在[-58,-40]和[40,58]范围内为真,否则为假”的表达式是: (x>= -58) && (x<= -40) && (x>=40) && (x<=58)|(x>= -58) && (x<= -40) || (x>=40) && (x<=58)|(x>= -58) | |(x<= -40) && (x>=40) || (x<=58)|(x>= -58) || (x<= -40) || (x>=40) || (x<=58)

能正确表示“当x的取值在&#91;-58，-40&#93;和&#91;40，58&#93;范围内为真，否则为假”的表达式是（）。 A: （x>=-58）&&（x<=-40）&&（x>=40）&&（x<=58） B: （x>=-58）∥（x<=-40）∥（x>=40）∥（x<=58） C: （x>=-58）&&（x<=-40）∥（x>=40）&&（x<=58）

（襄阳中考）用一条长40cm的绳子围成一个面积为64cm²的长方形．设长方形的长为xcm，则可列方程为（）。 A: x（20＋x）＝64 B: x（20－x）＝64 C: x（40＋x）＝64 D: x（40－x）＝64

假定16<X≤40，那么用边界值分析法，X在测试中应该取的边界值是： A: X=16，X=17，X=40，X=41 B: X=15，X=16，X=40，X=41 C: X=16，X=17，X=39，X=40 D: X=15，X=16，X=39，X=40

设有变量定义:x=(10,20,30)和y=&#91;10,20,30&#93;,以下正确的赋值语句是_______。 A: x(2)=40 B: x[2]=40 C: y(2)=40 D: y[2]=40

“int x=40；”，声明了一个字符型类的x变量，其默认值为40。

【单选题】#include <stdio.h> int x1 = 30, x2 = 40; void sub(int x, int y) { x1 = x; x = y; y = x1; } int main() { int x3 = 10, x4 = 20; sub(x3, x4); sub(x2, x1); printf(" %d, %d, %d, %d ", x3, x4, x1, x2); return 0; } A. 10, 20, 40, 40 B. 10,40, 40, 40 C. 20, 20, 40, 40 D. 10, 10, 40, 40

以4，9，1为为插值节点，求\(\sqrt x \)的lagrange的插值多项式 A: \( {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) B: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) + {1 \over {24}}(x - 4)(x - 9)\) C: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x +1) + {1 \over {24}}(x - 4)(x - 9)\) D: \( - {2 \over {15}}(x - 9)(x - 1) + {3 \over {40}}(x - 4)(x - 1) - {1 \over {24}}(x - 4)(x - 9)\)

You are offered an investment opportunity. Its outcomes and probabilities are presented in the following table. X P(X) –$1000 .40 $0 .20 +$1000 .40 The mean of this distribution is _____________.

设int x=40,y=28;，则执行x|=y;语句后，x的结果是