What is the difference between a monologue and soliloquy

Even the insistent cough of the woman next to him wasn't enough to draw his eyes away from the tiny type of the ancient book its pages were brittle and felt like they could crumble at the slightest disturbance he noticed the musty odor if each page as he carefully it over.

Which of the following sentences refers to a conflict between characters in "two kinds"?

(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.”)