Аннотация:It is proved that relative to random oracle A (with respect to the uniform measure) the following assertions hold: (1) there is a pair of disjoint NP^A-sets that are separable by no P^A-set, (2) there is a pair of disjoint Co-NP^A-sets that are separable by no P^A-set, and (3) there is an infinite Co-NP^A-set having no infinite NP^A-subset.