The number of species from the following in which the central atom uses sp 3 hybrid orbitals in its bonding…

${\mathrm{H}}_2\mathrm{O} \mathrm{has} {\mathrm{sp}}^3$ hybridisation and angular shape due to $2$ lone pair of electrons.

${\mathrm{NH}}_3 \mathrm{has} {\mathrm{sp}}^{3 }$ hybridised nitrogen atom and pyramidal shape due to $1$ lone pair of electrons.

${\mathrm{SiO}}_2 \mathrm{has} {\mathrm{sp}}^3$hybridised atoms, it is a network solid and the shape is tetrahedral around each silicon atom. 

${\mathrm{SO}}_2 \mathrm{has} {\mathrm{sp}}^2$ hybridised sulphur atom and the shape is V-shaped due to $1$ lone pair of electrons.

${\mathrm{BF}}_3 \mathrm{has} {\mathrm{sp}}^2$ hybridised boron atom and the shape is trigonal planar.

${\mathrm{BeCl}}_2\to \mathrm{sp}$

${\mathrm{CO}}_2\to \mathrm{sp}$

${\mathrm{CH}}_4\to {\mathrm{sp}}^3$

Hence the answer is $4$