The unique, characteristic pattern of epidermal ridges is visible as

The answer is finger prints, it is because finger prints are same as epidermal ridges in terms of their pattern characteristic because they are unique as people’s finger prints are not as the same as other people has in which, making them unique just like epidermal ridges.

heat a spark and oxygen

meteorologists would compare a new weather map with one 24 h old to see how fast a front is moving.