26. What is the name of the process by which nitrogen in the atmosphere is converted into a form that plants can use?
a) Nitrogen fixation
b) Photosynthesis
c) Respiration
d) Combustion
27. What is the name of the process by which oxygen in the atmosphere is converted into carbon dioxide by living organisms?
a) Photosynthesis
b) Respiration
c) Combustion
d) Carbon sequestration
28. What is the name of the layer of the Earth’s atmosphere where most of the ozone is located?
a) Stratosphere
b) Troposphere
c) Mesosphere
d) Thermosphere
29. What is the name of the process by which pollutants in the atmosphere are removed by rain?
a) Precipitation
b) Transpiration
c) Evaporation
d) Condensation
30. What is the name of the process by which carbon dioxide in the atmosphere is absorbed by plants during photosynthesis?
a) Respiration
b) Combustion
c) Carbon sequestration
d) Erosion
