National Geographics: Earth

What percentage of Earth's surface is covered by oceans?

• 30%

• 50%

• 70%

• 90%

What is the average surface temperature of Earth mentioned in the text?

• 59° F

• 70° F

• 80° F

• 100° F

According to the text, why is Earth considered a special spot in the solar system?

• Because of its distance from the sun

• Because it is the only planet known to harbor life

• Because of its unique shape

• Because of its extreme temperatures

How is Earth's atmosphere described in the text?

• A force field against solar radiation

• A source of solar radiation

• A barrier preventing exploration

• A hostile environment for living beings

What phenomenon on Earth is responsible for the creation of light shows known as auroras?

• Continental drift

• The axial tilt

• The atmosphere

• The rotation speed