Language is a system that consists of the development, acquisition, maintenance and use of complex systems of communication, particularly the human ability to do so; and a language is any specific example of such a system.
Indoor air quality (IAQ) influences the health and well-being of people but for the last 20 years there has been a growing concern about pollutants in closed environments, the difficulty in identifying them and their critical levels.
EN 
CS
DE
ES
FR
HU
IT
PL
PT
РУ
SK
TR
УК
AR
中文
