The number of species from the following in which the central atom uses $$\mathrm{sp}^3$$ hybrid orbitals in its bonding is __________.

$$\mathrm{NH}_3, \mathrm{SO}_2, \mathrm{SiO}_2, \mathrm{BeCl}_2, \mathrm{CO}_2, \mathrm{H}_2 \mathrm{O}, \mathrm{CH}_4, \mathrm{BF}_3$$

The total number of molecular orbitals formed from $$2 \mathrm{s}$$ and $$2 \mathrm{p}$$ atomic orbitals of a diatomic molecule is __________.

The total number of molecules with zero dipole moment among $$\mathrm{CH}_4, \mathrm{BF}_3, \mathrm{H}_2 \mathrm{O}, \mathrm{HF}, \mathrm{NH}_3, \mathrm{CO}_2$$ and $$\mathrm{SO}_2$$ is ________.

The total number of anti bonding molecular orbitals, formed from $$2 s$$ and $$2 p$$ atomic orbitals in a diatomic molecule is _______.