which of these is the best example of a sidebar that could be included in years of dust? an explanation of the dust bowl and the causes of dust storms a detailed description of the causes of the great depression. an in-depth story of how lange took the ""migrant mother"" photograph. a brief biography that describes pare lorentz’s life and film career

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.