At what time of day are dissolved oxygen levels most likely to be highest?

Harvey mixes two liquids. which observation of the new mixture most likely indicates a precipitate is forming?

Which position represents spring in the southern hemisphere? a) b) c) d)

Athe top of a hill, an athlete on a skateboard has x joules of mechanical energy. how much mechanical energy will she have at the bottom of the hill? ignore the effects of friction.