Sentences revolve around because these words function both as sentence subjects and as objects of verbs

Sentences revolve around nouns  because these words function both as sentence subjects and as objects of verbs. A noun is a word that functions as the name of some specific thing or set of things, such as living creatures, objects, places, actions, qualities, states of existence, or ideas.

chronological thinking is an indispensable tool to structure a historical narrative and to give meaning to a sequence of events. the final section presents the results of a survey to test the chronological thinking of lower secondary school students carried out by the educational research institute.