设集合U={1,2,3,4},A={1,2},B={2,4},则C_U(A∪B)=

A.{2}             B.{3}           C.  {1,2,4}       D.{1,4}

2.设集合U={1,2,3,4},A={1,2},B={2,4},则(A∪B)=

(A) {2}                 (B){3}                  (C)  {1,2,4}                 (D) {1,4}

设集合U={1,2,3,4,5},A={1,3,5},B={2,3,5},则_U(A∩B)等于

A.{1,2,4}                                                               B.{4}

C.{3,5}                                                                  D.

设集合U={1,2,3,4,5},A={1,2,3},B={2,5},则A∩（B）等于（    ）

A.{2}                 B.{2，3}         C.{3}            D.{1，3}

 设集合U={1 ,2 ,3 ,4}，M={1 ,2 ,3},N={2,3,4},则=（  ）

A．{1,2}        B.{2，3}       C．{2,4}         D．{1,4}