And water solution whose ph is 4. a) is always neutral. b) is always basic. c) is always acidic. d) might be neutral, basic or acidic

h

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: