  The semi-inclusive properties of the system of neutral and charged particles
with net charge equal to zero are considered in the grand canonical, canonical
and micro-canonical ensembles as well as in micro-canonical ensemble with
scaling volume fluctuations. Distributions of neutral particle multiplicity and
charged particle momentum are calculated as a function of the number of charged
particles. Different statistical ensembles lead to qualitatively different
dependencies. They are being compared with the corresponding experimental data
on multi-hadron production in $p+p$ interactions at high energies.
