The following passage from "A Horseman in the Sky" introduces which element of the story's setting? Select all that apply. So tensely was he strung, that a bunch of quail, exploding into flight from under his horse’s nose, startled him to such an extent that automatically, instantly, he had reined in and fetched the carbine halfway to his shoulder. He grinned sheepishly, recovered himself, and rode on. So tense was he, so bent upon the work he had to do, that the sweat stung his eyes unwiped, and unheeded rolled down his nose and spattered his saddle pommel. The band of his cavalryman’s hat was fresh-stained with sweat. The roan horse under him was likewise wet. It was high noon of a breathless day of heat.