Chemical Bonding And Molecular Structure

Observe the following list of molecules. Number of polar and non-polar molecules are respectively

$\mathrm{NH}_3, \mathrm{BF}_3, \mathrm{NF}_3, \mathrm{H}_2 \mathrm{~S}_2, \mathrm{CO}_2, \mathrm{CH}_4, \mathrm{CHCl}_3, \mathrm{H}_2 \mathrm{O}$