Smoking increases . . . . . . content in blood and reduces the concentration of haem-bound oxygen. Fill in the blank suitably.

Tobacco smoke contains carbon monoxide,which

In heavy smokers,the alveoli of the lungs are enlarged and damaged,which reduces the surface area for the exchange of respiratory gases. This condition is called:

Give scientific reason: $(1)$ Smoking is a cause of hypertension.

Assertion $A$: Pneumonia is a serious respiratory disease.
Reason $R$: The accumulation of fluid in the alveoli and bronchioles prevents sufficient oxygen from reaching the lungs.
Which option is correct for Assertion $A$ and Reason $R$?

Which of the following is associated with pneumonia?