Which of the following is a weak base?
O
Cu(OH)2
Ba(OH)2
O
LiOH
O Ca(OH)2

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: