Which two substances are elements? A. sand and air B. salt and sand
C. iron and helium
D. helium and water

C, iron and helium are elements since they consist of only one type of atoms

“foliation in geology refers to repetitive layering in metamorphic rocks. each layer can be as thin as a sheet of paper, or over a meter in thickness. the word comes from the latin folium, meaning "leaf", and refers to the sheet-like planar structure. “i found this on google i hope it you

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.