surface
2. What is the percentage of oxygen in Earth's atmosphere?
A. 10% B. 21% C. 50 % D. 75%
3. Which layer of the atmosphere has an air pressure that decreases
as altitude increases?
A. exosphere
B. mesosphere
c. thermosphere
D. all of the above
4. What area of human activity is responsible for the highest
greenhouse gas emissions?
A. agriculture
B. industrial
C. transport
D. energy supply
5. What layer of the atmosphere is the ozone layer located in?
A. mesosphere B. stratosphere C. thermosphere D. troposphere
6. What is the correct order of the layers of the atmosphere, starting
with the layer closest to the earth's surface?
A. stratosphere, troposphere, exosphere, mesosphere,
thermosphere
B. troposphere, stratosphere, mesosphere,
exosphere, thermosphere
C. troposphere, stratosphere, mesosphere, thermosphere,
exosphere
D. troposphere, stratosphere, thermosphere,
exosphere, mesosphere
7. Which of the following human activities contribute to the
increase in the greenhouse gas emissions to the atmosphere?
A. burning of fossil fuels
B. proper waste disposal
C. planting more native trees
D. volunteer at a marine sanctuary​