双基限时练(四)集合的交集和并集基 础 强 化1若集合MxN|x8,N1,4,5,7,则MN等于()A4,5,7B1,2,3,4,5,6,7C1,2,3,4,5,6,7,1,4,5,7 D1,1,2,3,4,5,6,7解析M1,2,3,4,5,6,7,则集合M与N的全部元素组成的集合是MN1,1,2,3,4,5,6,7答案D2已知集合A1,0,1,Bx|1x1,则AB()A0 B1,0C0,1 D1,0,1解析集合B含有整数1,0,故AB1,0答案B3集合A0,2,a,B1,a2,若AB0,1,2,4,16,则a的值为()A0 B1C2 D4解析由AB0,1,2,4,16可知,a4,且a216,a4.答案D4已知集合Ax|1x2,集合Bx|2x3,则下列关系中正确的是()AABBAB2CABx|1x3DABx|1x2解析AB,ABx|1xa2,a2.B时,或a3,或a2.综上所述,a3,或a2.品 味 高 考13设集合Mx|x22x0,xR,Nx|x22x0,xR,则MN()A0 B0,2C2,0 D2,0,2解析Mx|x(x2)0,xR0,2,Nx|x(x2)0,xR0,2,所以MN2,0,2答案D