Week 23 Science

How do trees help the geosphere?

• They provide oxygen.
• They keep water clean.
• They prevent soil erosion.
• They offer shelter to squirrels.

Why are trees called “the lungs of the Earth”?

• They clean soil pollution.
• They limit noise pollution.
• They absorb air pollution.
• They reduce water pollution.

What is deforestation?

• burning trees for warmth
• harvesting fruit from trees
• cutting down lots of trees
• using trees to build houses

How many square miles of forest are cleared every 10 years?

• 100,000
• 350,000
• 500,000
• 780,000

Which basic need do trees NOT supply?

• air
• food
• shelter
• water

Why would it take a long time for cleared land to become forest again?

• Grasses and flowers block sunlight.
• Trees require animals to live in them.
• It takes a long time for trees to grow.
• Trees do not like to grow on bare soil.

What is a watershed?

• all of the water in a lake
• a forest with a large river
• all precipitation that falls onto soil
• a region that drains into one outlet

Why does the water in a watershed end up at the same body of water?

• All precipitation falls into it.
• Water vapor is attracted to it.
• Animals carry all of the water to it.
• The land is sloped in that direction.

How might humans make a watershed unhealthy?

• cutting down all of the trees
• planting a backyard garden
• drinking water from a faucet
• stopping soil erosion on rivers

Where does all water on Earth eventually flow?

• marshes
• oceans
• reservoirs
• springs