Baby caitlen is about to turn one year old. she loves to play peek-a-boo and acts so surprised each time a hidden face appears behind her dad's hands. why is she surprised?

Caitlen doesn't that each times her dad hides he still exists.

Explanation:

Baby Caitlen is still one year old this means that she is still learning that things still remain when they disappear and come back in sight. The psychologist Jean Piaget called this principle "object permanence". As the baby grows older this effect seems to wean off. The baby is learning that things do not disappear but are merely out of sight.

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:

hypostyle hall;