问题
选择题
设全集u={x|x<9,x∈N+},A={1,2,3},B={3,4,5,6},则Cu(A∪B)=[ ]
A.{7,8}
B.{7,8,9}
C.{3,4,5,6,7,8}
D.{6,7,8,9}
答案
答案:A
设全集u={x|x<9,x∈N+},A={1,2,3},B={3,4,5,6},则Cu(A∪B)=[ ]
A.{7,8}
B.{7,8,9}
C.{3,4,5,6,7,8}
D.{6,7,8,9}
答案:A