Build the strong bones that athletes depend on, and iron carries oxygen to muscles.
calcium
vitamin c
carbohydrates
iron

The answer is calcium

Pstt , remember it with milk , milk contains calcium and so it's white , Bones are also white !
That's why we drink milk for stronger bones ;)

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.