At least two examples
of Chemical Formula

h20 (water duh)

C9H13N (Amphetamine)

C6h1206 (glucose)

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: