What does 'the matter in your body has been on earth for billions of years.' mean? !

Does indrect sunlight does not pose any danger to the skin

Is it bad to have a headache all day long?

Hiv is inactivated in the laboratory after a few minutes of sitting at room temperature, but the flu virus is still active after sitting for several hours. what are the practical consequences of these findings? a) hiv can be transmitted more easily from person to person than the flu virusb) the flu virus can be transmitted more easily from person to person than hivc) this property of hiv makes it more likely to be a pandemic than the flu virusd) disinfecting surfaces is more important to reduce the spread of hiv than the flu