已知M=｛m|m=2k,k∈Z},X={x|x=2k+1,k∈Z},Y={y|y =4k+1,k∈Z}则（A.x+y∈MB.x+y∈Xc.x+y∈YD.x+y∉M

已知M=｛m|m=2k,k∈Z},X={x|x=2k+1,k∈Z},Y={y|y =4k+1,k∈Z}则（A.x+y∈MB.x+y∈Xc.x+y∈YD.x+y∉M
已知M=｛m|m=2k,k∈Z},X={x|x=2k+1,k∈Z},Y={y|y =4k+1,k∈Z}则（
A.x+y∈M
B.x+y∈X
c.x+y∈Y
D.x+y∉M

已知M=｛m|m=2k,k∈Z},X={x|x=2k+1,k∈Z},Y={y|y =4k+1,k∈Z}则（A.x+y∈MB.x+y∈Xc.x+y∈YD.x+y∉M
选A
X,Y都为奇数集,x+y便是偶数,M是偶数集,所以x+y∈M