In an ice crystal, each water molecule is hydrogen bonded to ____________ neighbouring molecules.

The number of species from the following which have square pyramidal structure is _________

$$\mathrm{PF}_{5}, \mathrm{BrF}_{4}^{-}, \mathrm{IF}_{5}, \mathrm{BrF}_{5}, \mathrm{XeOF}_{4}, \mathrm{ICl}_{4}^{-}$$

The number of molecules or ions from the following, which do not have odd number of electrons are _________.

(A) NO$$_2$$

(B) ICl$$_4^ - $$

(C) BrF$$_3$$

(D) ClO$$_2$$

(E) NO$$_2^ + $$

(F) NO