2: 2. Which gas makes up the majority of Earth's atmosphere?
a. Oxygen
b. Nitrogen
c. Carbon dioxide
d. Hydrogen
3: 3. What gas do plants absorb from the air during photosynthesis?
a. Oxygen
b. Carbon dioxide
c. Nitrogen
d. Hydrogen
4: 4. What is the approximate percentage of oxygen in the air?
a. 21%
b. 50%
c. 78%
d. 10%
5: 5. Which layer of the atmosphere contains the ozone layer?
a. Troposphere
b. Stratosphere
c. Mesosphere
d. Thermosphere
6: 6. What is the role of the ozone layer in the atmosphere?
a. Absorbing ultraviolet (UV) radiation
b. Producing oxygen
c. Absorbing carbon dioxide
d. Creating rain
7: 7. Which gas do humans and animals inhale from the air?
a. Nitrogen
b. Oxygen
c. Carbon dioxide
d. Hydrogen
8: 8. What is the process by which plants release water vapor into the air?
a. Transpiration
b. Condensation
c. Evaporation
d. Precipitation
9: 9. Which layer of the atmosphere is closest to the Earth's surface?
a. Troposphere
b. Stratosphere
c. Mesosphere
d. Thermosphere
10: 10. What is the process of the Earth's surface warming up due to the sun's rays?
a. Conduction
b. Convection
c. Radiation
d. Insulation
Learn New Vocabulary
Word: wheedle
Meaning: influence or urge by gentle urging, caressing, or flattering
Sentences: On one level, I expected incessant flattery in attempts to wheedle equipment or even money from American forces.New York Times (Aug 16, 2010)
