An organism that is made up of more than one cell.
It ifs less dense than water, it will float. If it is more dense then water, it will sink. If an object weighs more than the same amount of water, then it will sink. But if it weighs less, it will float.
The right answer is HEPA filter.
A HEPA filter (High Efficiency on Particles Air) can filter up to 99.97% of 0.3μ aerial particles.
These filters are used to clean the air and retain suspended particles (dust, pollen, bacteria etc.) and other particles that can cause respiratory allergy in sensitive subjects.
They are very used in sterile rooms
