  To understand the recently observed high temperature superconductivity in the
monolayer CuO$_2$ grown on the Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ substrates,
we propose a two band model of the hybridized oxygen $p_x$ and $p_y$ orbitals
with the proximity effect of the substrate. We demonstrate that both the nodal
and nodeless d-wave superconducting states can be induced by the proximity
effect, depending on the strengths of the pairing parameters.
