Filtering equipment is sorted by media type
Through the settings to block spam, so that the information displayed on the computer screen as much as possible to meet the requirements.
So that contaminated liquid is cleaned to production, life needs of the state, that is, so that the liquid to a certain degree of cleanliness.
So that the pollution of the air is clean to the production, life needs of the state, that is, to achieve a certain degree of cleanliness of the air.
With the principle of absorption will be different colors of light separation
