Compare surface, subsurface, and placer mining in terms of damage to the environment

How can scientists test their ideas about the origin of the universe if they can't physically interact with or study?

Which organelle breaks down sugar molecules that supply energy to the cell ?

The structure of a dna molecule is best described as a. one long strand of nucleic acids b. two strands of dna nucleotides joined by hydrogen bonds c. two strands of amino acids joined by hydrogen bonds d. one long strand of amino acids