What is a good thing to do for you personally in terms of personal environmental safety?

Not true , they can fall or something

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. 

To this question it will be choice one

Small intestine because that is the organ which absorbs nutrients