11. Which of the following is NOT a component of soil?
a) Sand
b) Water
c) Air
d) Fire
Answer: d
12. What is the process by which nitrogen is converted into a form that plants can use called?
a) Nitrogen fixation
b) Photosynthesis
c) Respiration
d) Decomposition
Answer: a
13. Which of the following is NOT a greenhouse gas?
a) Carbon dioxide
b) Nitrogen
c) Methane
d) Water vapor
Answer: b
14. Which of the following is NOT a type of fossil fuel?
a) Coal
b) Oil
c) Natural gas
d) Solar energy
Answer: d
15. What is the term for the study of the interactions between living organisms and their environment?
a) Ecology
b) Geology
c) Chemistry
d) Physics
Answer: a
