Tobacco smoke contains carbon monoxide,which

What is the color of the organs in the body during cyanosis?

Which of the following is a characteristic of asthma?

In the common cold,which of the following occurs?

$A$: Asthmatic patients use bronchodilator drugs as well as inhalers for symptomatic relief.
$R$: Asthma is characterized by the spasm of smooth muscles in the wall of bronchioles due to allergens.

Chronic respiratory disorders like $.......$ are caused by pollen grains.