The Romans believed because of knowledge obtained from the Greeks that diseases were connected to what ? And a a result began to develop what ?

Smoking damages the respiratory system by inhalation of a foreign substance, that is absorbed and residue is left behind on our lungs sponge like substance. the gas that is inhaled also increase your blood pressure and dilates your blood vessels. also the process of inhaling and exhaling the smoke it causes irritation to the throat and mouth. smoking can cause lung cancer and other respiratory and circulatory diseases. 

What happens to the influenza virus every 20-40 years and why?

Answer weekly planner;