31. What is the name of the process by which water vapor in the atmosphere is converted into liquid or solid form?
a) Condensation
b) Precipitation
c) Evaporation
d) Transpiration
32. What is the name of the layer of the Earth’s atmosphere where most weather balloons are launched?
a) Stratosphere
b) Troposphere
c) Mesosphere
d) Thermosphere
33. Which of the following is not a primary air pollutant?
a) Carbon monoxide
b) Nitrogen oxides
c) Ozone
d) Sulfur dioxide
34. What is the name of the process by which energy from the Sun is trapped by greenhouse gases in the Earth’s atmosphere, causing the planet to warm?
a) Ozone depletion
b) Acid rain
c) Smog
d) Greenhouse effect
35. What is the name of the atmospheric layer above the thermosphere where the atmosphere gradually merges with outer space?
a) Exosphere
b) Stratosphere
c) Mesosphere
d) Troposphere
