All staphylococci can be differentiated from all streptococci because only staphylococci produce the enzyme that is easily detected in the lab.

The enzyme is catalase.

Explanation:

The Staphylococcus produces enzyme catalase which convert hydrogen peroxide to water and oxygen during catalase test. That is the reason why they are positive to catalase test and Streptococcus is negative, because it does not produce enzyme catalase during the test.

answer: ice crystals in air

the water from the water body or another source of water gets evaporated as water vapor as an effect of heat on water. these water vapor rises in the upper layers of the earth atmosphere under high atmospheric pressure. the atmospheric pressure of these water molecules starts to decrease due to the effect of cold air. the invisible water vapor condenses into visible water droplets and ice crystals.these ice crystals and water droplets being less denser than the surrounding air floats on air as clouds.