Identify the following sections of the textbook.
nouns and adjectives
noun
plural nouns
nouns

if this question from odyssey ware

chapter- nouns and adjectives

text- noun

subsection- plural nouns

unit- nouns

Noun:   a word (other than a pronoun) used to identify any of a class of people, places, or things  common noun, or to name a particular one of these  proper noun. 
adjective :   a word naming an attribute of a noun, such as  sweet,  red, or  technical.

plural definition. the grammatical category in  nouns, pronouns, and verbs that refers to more than one thing. most  nouns  become  pluralwith the addition of -s or -es: hats, chairs, dishes, countries, and so on. some  nouns  form the  plural  in other ways, as in children, feet, geese, and women.

Therefore sounds more formal and you know english teachers