Risk for developing lung cancer for smokers varies due to all of the following except
a. factors like frequency of smoking and age of starting smoking.
b. inconsistently collected data.
c. other lifestyle risk factors.
d. variations in depth of inhalation of cigarette smoke.

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. 

Yes i have used it before

Anice cardio work out.