Can someone rewrite this in their own words please. Open Depth of field is controlled by changing the aperture setting on your camera. Like your eye, a camera lens has an iris inside that can open or close to let in more or less light.
A shallow depth of field is the small or narrow area in an image that is in focus. Often, the background is blurred while only the subject stays in focus.

(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.”)