In which figures 15-3 which gas makes up the greatest percentage of earth's atmosphere

What is the "great pacific garbage patch"? (a) a large area of marine debris concentrated by rotating ocean currents (b) a large area around the pacific rim where debris collects from natural disasters such as tsunamis (c) an area in the pacific ocean where trash is intentionally dumped due to lack of landfill availability (d) a large trash dump located in hawaii

From the standpoint of geography, a is an internal rendering of an individual's known world

What is the border between layers a through f and layer g called?