What is the $s$-character content in an $sp^3$ hybrid orbital?

Identify the correct set of molecules with different geometries and central atoms with different hybridisations.

What is the decreasing order of carbon-carbon single bond length in the following compounds?
$(I) CH_2 = CH - C \equiv CH$
$(II) CH \equiv C - C \equiv CH$
$(III) CH_3 - CH = CH_2$
$(IV) CH_2 = CH - CH = CH_2$

Total number of vacant orbitals in the valence shell of sulphur when it undergoes the formation of $SF_4$.

Choose the correct code of characteristics for the given order of hybrid orbitals of the same atom,$sp < sp^2 < sp^3$:
$(i)$ Electronegativity
$(ii)$ Bond angle between same hybrid orbitals
$(iii)$ Size
$(iv)$ Energy level

With which of the given pairs does $CO_2$ resemble in terms of structure?