11. In a food chain, which is most likely able to bring back the nutrients/materials to its reservoir in the environmen

A. Producers B. Consumers  C. Decomposers  D. All of the above 

12. The conversion of nitrogen from the soil into nitrogen gas is called 

A. Nitrogen Fixation  B. Denitrification  C. Decomposition  D. Respiration 

13. Which of the following compound is readily available in the atmosphere

A. NO3  B. NH3  C. NO  D. N2 

14. How do humans facilitate the cycle of Carbon in the atmosphere? 

A. by planting trees  B. by burning fossil fuels C. by using organic fertilizers D. by throwing garbage into bodies of water 

15. The process in which water moves between places and changes from one for another is known as the:

A. Carbon Cycle  B. Nitrogen Cycle  C. Hydrologic cycle  D. Oxygen Cycle​