"The environment consists of four segments as under:
1. Atmosphere: The atmosphere implies the protective blanket of gases, surrounding the earth:
(a) It sustains life on the earth.
(b) It saves it from the hostile environment of outer space.
(c) It absorbs most of the cosmic rays from outer space and a major portion of the electromagnetic radiation from the sun.
(d) It transmits only here ultraviolet, visible, near infrared radiation (300 to 2500 nm) and radio waves. (0.14 to 40 m) while filtering out tissue-damaging ultraviolet waves below about 300nm. The atmosphere is composed of nitrogen and oxygen. Besides, argon, carbon dioxide, and trace gases.
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