Gas has chemicals in it so it well affect you're lungs
Ozone
Radon gas.
The effects of the Columbian Exchange were both harmful and beneficial. This is because the diseases caused native Americans to die but new goods were spread to different areas.
Helpful is a word that describes something that is useful and gives aid. The opposite of helpful would be unhelpful, useless, destructive, damaging, worthless, or hindrance
12 for gas intake and air both
lion are useful and harmful
it is useful
That depends on what effect is desired; If you like to breathe, it is a useful gas; If you prefer that your car (or whatever) not be rusty (oxidized), then it is a harmful gas.
i think its both harmful and useful
changes both harmful and useful
both
Yes.
both, depending on circumstances
if you burn natural gas in a boiler it is useful or harmful
In what ways is antarctica be useful for humans
It is both, and both to a very great degree.
Animals that produce poison.