  Low lying states of a 2D electron-hole system contain electrons and one or
more types of charged excitonic complexes. Binding energies and angular momenta
of these excitonic ions, and the pseudopotentials describing their interactions
with electrons and with one another are obtained from numerical studies of
small systems. Incompressible fluid ground states of such multi-component
plasmas are found in exact numerical diagonalizations. A generalized composite
Fermion (CF) picture involving Chern--Simons charges and fluxes of different
types is proposed and shown to predict the low lying states at any value of the
magnetic field.
