How to draw resonance structures?

Q. Draw all the possible resonance structures for Benzaldehyde.

Q. Draw all the possible resonance structures for Phenol.

Q.

Draw the resonance structures of the following compounds:

\(A\):


\(B\):


\(C\):

Q. Pyrroles are five-membered nitrogen-containing heterocyclic compounds present in heme which is a constituent of hemoglobin. Draw all the significantly contributing resonance structures of pyrrole (K).

Q. How many resonance structures does $C{O}_2$ have?