Which were all add carbon dioxide to carbon cycle on earth?
A. Photosynthesis
B. Respiration
C. Decay of organic matter
D. Volcanic action
Choose the correct answer from the below codes.
A,B,C
B,C only
A and D
A,B,C, and D
Which were all add carbon dioxide to carbon cycle on earth?
A. Photosynthesis
B. Respiration
C. Decay of organic matter
D. Volcanic action
Choose the correct answer from the below codes.