A marks the boundary between the outer edges of two contrasting air masses, and lies in an area of relatively pressure.

within these regions are all the major types of biomes in the world. a biome is a community of animals and plants spreading over an extensive area with a relatively uniform climate. some diverse biomes represented in north america include desert, grassland, tundra, and coral reefs.

answer called a epicycle;

a. i. only is correct.