What in the world is not chemistry

Without chemistry we can't imagine our life.

Explanation:

our lightbulbs, oxygen, and other compunds are not discovered so we can't survive because we don't know the uses of things.

in cartography, a contour line (often just called a "contour") joins points of equal elevation (height) above a given level, such as mean sea level. a contour map is a map illustrated with contour lines, for example a topographic map, which thus shows valleys and hills, and the steepness or gentleness of slopes.

explanation: