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ScienceCLASS 9CBSE

answered 27 Mar 2026

Oxygen is returned to the atmosphere mainly by (a) burning of fossil fuel (b) respiration (c) photosynthesis fungi

A.VERIFIED ANSWERfact-checked by tutors

Soln:

Answer is (c) photosynthesis

Explanation:

Plants take CO2 from environment and they return back oxygen by a process called photosynthesis.

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