The number of species from the following that have pyramidal geometry around the central atom is _________

$$\mathrm{S}_2 \mathrm{O}_3^{2-}, \mathrm{SO}_4^{2-}, \mathrm{SO}_3^{2-}, \mathrm{S}_2 \mathrm{O}_7^{2-}$$

Number of molecules/ions from the following in which the central atom is involved in $$\mathrm{sp}^3$$ hybridization is ________.

$$\mathrm{NO}_3^{-}, \mathrm{BCl}_3, \mathrm{ClO}_2^{-}, \mathrm{ClO}_3$$

Which one of the following molecules has maximum dipole moment?