Since the origin of life on Earth, plants, animals, and microorganisms have obtained an important part of their sustenance from the atmosphere&#151;carbon, hydrogen, and oxygen for photosynthesis and respiration;
(plants, animals, and microorganisms; have obtained; an important part of their sustenance; from the atmosphere&#151; T:Since the origin of life on Earth)
plants, animals, and microorganisms
have obtained
an important part of their sustenance from the atmosphere&#151 T:Since the origin of life on Earth