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: furnish
Meaning: provide with objects or articles that make a room usable
Sentences: Instead, according to court documents, the money went toward furnishing mansions, flying in private jets, and retaining a $120,000-a-year personal hairstylist.BusinessWeek (Feb 1, 2012)
Fact: A single photon (light particle) takes thousands of years to travel from the core of the sun to its surface, but only 8 minutes to travel from the sun to Earth.
Facts of Digital World
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