Acid rain is caused by which of the following?
nitrogen compounds in plants
nitrogen compounds in the air
nitrogen compounds in the soil
nitrogen compounds in lakes and rivers

In dna, only the_ varies from one nucleotide to another. base phosphate sugar amino acid

Which set of characteristics best describes sedimentary rock? a) largest type of rock, made of organic matter, hardest type of rock b) often contains layers, forms near sources of water, contains fossils c) least abundant type of rock, made of other rocks, made mostly of minerals d) most abundant type in earth's crust, made of magma/lava, contains no fossils

Approximately percent of the energy created by cell metabolism is used by the body to carry on its normal functions, such as respiration, digestion, reproduction, muscular movement, circulation, and cellular regrowth.