G locate and identify the functional groups in (a) propylene glycol, one of the major ingredients used in electronic cigarettes; (b) glutaric acid, produced in the body during the metabolism of lysine and tryptophan; (c) lactic acid, from sour milk; and (d) phenylalanine, an amino acid found in proteins.

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.

a) carbon, hydrogen

b) carbon, hydrogen, oxygen, nitrogen

c) carbon, hydrogen, oxygen, nitrogen, phosphorus

d) sugar

e) amino acid

f) nucleotide