Which of the following organs is most affected by a deficiency of $O_2$ in humans?

Give differences between Asthma and Emphysema.

$A$: Emphysema is a chronic obstructive pulmonary disease,causing irreversible distension and loss of elasticity of the alveoli.
$R$: Emphysema is preventable if chronic exposure to smoke (cigarette and others) and pollutants is avoided.

What is the cause of lung cancer in coal miners?

Tobacco smoke contains carbon monoxide which

Asthma is a respiratory disease concerned with