∵全集U={0,1,2,3,4},集合A={a| a?1 a?4 ≤0,a∈Z}={1,2,3,4},集合B={b|b(b2-5b+6)=0}={0,2,3},∴集合A∩B={2,3},?UB={1,4},(?UA)∪B={0}∪{2,3}={0,2,3}.