what is the source of walking on snow thermal energy

Other than earth, is also known to have magnetic pole reversal? a: venus b: mars c: earths moon d: the sun

How much time has elapsed from the very beginning of "the memior of the conquistador bernal diaz del castillo" to the end? a. castillo's whole life b. a quarter of an hour c. a few weeks d. a decade

Some plants have reproductive structures that them reproduce using natural forces or animals. how does the reproductive structure shown here ensure the reproductive success of plants?