George splits a bagel in half and places both sides of the bagel in a toaster. He turns on the toaster, and within a minute the bagel pops out, brown and evenly toasted. What type(s) of heat transfer toasted the bagel? A. conduction
B. radiation
C. convection
D. conduction and convection

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: