Question

1. what is the main organ of the respiratory system?

Explanation:

The respiratory system is responsible for gas exchange (taking in oxygen and expelling carbon dioxide). The lungs are the primary organs where this gas exchange occurs. Other parts of the respiratory system like the trachea, bronchi, etc., are passageways that conduct air to and from the lungs. So, the main organ is the one where the key function (gas exchange) predominantly happens.

Answer:

Lungs