How do collective nouns differ from plural nouns?

Which is not among the style choices a writer would use, if he or she is trying to establish a formal writing style/

(1) fire extended humans’ geographical boundaries by allowing them to travel into regions that were previously too cold to explore. (2) it also kept predators away, allowing early humans to sleep securely. (3) fire, in fact, has been a significant factor in human development and progress in many ways. (4) other obvious benefits of fire are its uses in cooking and in hunting. (5) probably even more important, however, is that learning to control fire allowed people to change the very rhythm of their lives. (6) before fire, the human daily cycle coincided with the rising and setting of the sun. (7) with fire, though, humans gained time to think and talk about the day’s events and to prepare strategies for coping with tomorrow. the sentence that expresses the main idea is: (type the number of the sentence. then click “go.”)

Read the passage. then, identify the theme that is supported by the passage. most ships cannot survive a terrible thunderstorm. the ocean is an angry beast that will tame any who try to control it. the gods have the power to control human destiny. men are willing to die to eat the delicious cattle of the gods.