The function of beta-galactosidase is
a. break down glucose
b. produce glucose
c. break down lactose
or d. produce lactose

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:

a polar bond is formed when electrons are shared unevenly between atoms