I Would think it would be C Since Humans can't live 500 years but then yet again it is light years not regular years i think if you find how man years is 500 light years the that could help you in finding the answer
Air & noise pollution
Quarry waste
Damage to biodiversity
Heres the best help i can give you There is a couple different ways to determine if a bond is ionic or covalent. By definition, an ionic bond is between a metal and a nonmetal, and a covalent bond is between 2 nonmetals. So you usually just look at the periodic table and determine whether your compound is made of a metal/nonmetal or is just 2 nonmetals
The Curiosity rover found sulfur compounds in rocks and carbon in organic compounds like propane, butene, benzene, toluene and thiophene.
It detected methane, not in soil samples, but in the Martian atmosphere.
It did not discover helium in underground pockets. The hole it can drill is only 5 cm deep.
That would be true, since most other stats include helium, calcium, etc
