问题
选择题
已知全集U={1,2,3,4},集合M={1,3,4},N={1,2},则集合{2,3,4}=( )
A.CUM∪CUN
B.CUM∩CUN
C.M∪N
D.M∩N
答案
CUM={2},CUN={3,4}
选项A,CUM∪CUN={2,3,4},满足题意;
选项B,CUM∩CUN=∅,不满足题意;
选项C,M∪N={1,2,3,4},不满足题意;
选项D,M∩N={1},不满足题意.
故选A.