命令$echox‟*‟y的执行结果是()
设U是所有属性的集合,X、Y、Z都是U的子集,且Z=U-X-Y。下面关于多值依赖的叙述中,哪个是正确的?A.若X→→Y,则X→YB.若X→Y,则X→→YC.若→→Y,且Y'Y,则X→→Y,D.若X→→Y,则X→Z
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执行下列命令后,显示的结果是 X=50 Y=100 Z=“X+Y” ?50+&ZA.50+&ZB.50+X+YC.200D.数据类型不匹配
计算z的值,当x大于等于y时,z=x;否则z=y。下列语句错误的是( )A.If x>=y Then z=x:z=yB.If x>=y Then z=x Else z=yC.z=y:If x>=y Then z=xD.If x<y Then z=y Else z=x
计算z的值,当x大于y时,z=x;否则z=y。下列语句错误的是( )A. If x>=y Then z=x : z=yB If x>=y Then z=x Else z=yC. z=y : If x>=y Then z=xD. If x
命令$echo x’*’y的执行结果是()A.x*yB.x’*’yC.x’*yD.‘x*y’
计算z的值,当x大于y时,z=x;否则z=y。下列语句错误的是A.If x>=y Then z=x:z=yB.If x>=y Then z=x Else z=yC.z=y:If x>=y Then z=xD.If x<=y Then z=y Else z=x
X: He likes dogs. Y: He likes animals. The relationship of X and Y is that“__________”.A.X is synonymous with Y B.X is inconsistent with Y C.X entails Y D.X presupposes Y