问题
单项选择题
What operation on relations R and S produces the relation shown below
A． Union
B． Difference
C． Intersection
D． Division
答案
参考答案：A
搜题请搜索小程序“爱下问搜题”
What operation on relations R and S produces the relation shown below
A． Union
B． Difference
C． Intersection
D． Division
参考答案：A
