He completed her work change into passive voice

Which sentence from the story is an example of conflict? “here were many men, and countless dogs, and buck found them all at work.” “buck had been purposely placed between dave and sol-leks so that he might receive instruction.” “by afternoon, perrault, who was in a hurry to be on the trail with his despatches, returned with two more dogs.” “that night buck faced the great problem of sleeping.”

Can someone me with my essay? editing?

(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.”)