Endocarditis occurs when bacteria infect the bloodstream and attach themselves to the inner lining of the heart or a defective heart valve. These bacteria are .

Streptococcal or Staphylococcal bacteria

Explanation:

They attach themselves to the inner lining of the heart making it to becme inflamed and casing damage to the heart valves.

one would be wind another would be water density

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.