Which statement describes how hail is formed? Ice crystals collect on the rain drops, forming large chunks of ice.
Liquid water freezes on solid precipitation in layers, creating large chunks of ice.
Water vapor condenses on solid precipitation that is blown by gusts of wind.
Water vapor freezes into ice crystals that fall through different layers of air.

Consider a culture medium on which only gram-positive organisms such as staphylococcus aureus colonies can grow due to an elevated nacl level. a yellow halo surrounds the growth, indicating the bacterium fermented a sugar in the medium, decreasing the ph as a result and changing the color of a ph indicator chemical. this type of medium would be referred to as a differential and enrichment culture.