A Thirsty World

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

• 50%

• 70%

• 90%

What is the primary source of freshwater on Earth?

• Rivers and streams

  
  

• Glaciers and ice caps

  
  

• Lakes and ponds

  
  

Which process involves water turning into vapor due to the sun's heat?

• Condensation

• Evaporation

• Precipitation

The world's largest ocean is:

• Pacific Ocean

• Atlantic Ocean

  
  

• Indian Ocean

  
  

What is the term for the regular rise and fall of the ocean's surface caused by the moon's and sun's gravitational pull?

• Waves

• Currents

• Tides

What is the average temperature at which water freezes in Celsius?

• 0 degrees Celsius

• 100 degrees Celsius

• -10 degrees Celsius

Which of the following is a form of water that falls to the ground, including rain, snow, sleet, and hail?

• condensation

• evaporation

• precipitation

What is the process of removing salt and other impurities from seawater to make it suitable for drinking?

• filtration

• desalination

• filtration

Water is essential for human survival. Approximately how many days can a person survive without water?

• 1-2 days

• 5-7 days

• 10-14 days