01: posttest 1-parts of speech
which statement is true?
an adjective is a word that modifies a verb, an adverb, or another adjective.
adverbs can modify adjectives, and adjectives can modify adverbs.
some words that are usually nouns can function as adjectives.
an adverb can only modify a noun or a pronoun

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.