  When the energy of the heavy quark is comparable with its mass, it is natural
to attribute this heavy quark to the hard part of the reaction. At large
energies, this approach is impractical due to large logarithms from intensive
QCD radiation affecting both inclusive and differential observables. We present
a formalism for all-order summation of such logarithms and reliable description
of heavy-quark distributions at all energies. As an illustration, we calculate
angular distributions of B-mesons produced in neutral-current events at large
momentum transfers at the ep collider HERA.
