06 Soil

Soil is the top layer of much of the Earth's land surface. It is a mixture of broken rock, humus — bits of dead plants and animal waste — air, and water. Different kinds of soil have different sizes of rock particles and can be found in various places.

Soil is lost when it is blown by wind or carried away by rain or rivers. Mountain soil is gradually lost due to gravity if the trees that hold it are logged. This is called soil erosion. It can be prevented by keeping trees healthy.

Word List

waste : material that comes out of animals after they eat

gradually : slowly

gravity : the force that pulls objects down to Earth

particles : very small pieces

logged : when trees are cut down

prevented : stopped

You Practice

I. Answer the following questions.

1） What is soil made from?

2） How is soil lost?

3） How can soil erosion be prevented?

4） How is soil different in various places?

II. Read the sentences carefully. Write Yes or No for each one.

____ 1） Cutting down trees is good for soil.

____ 2） Soil is sometimes carried away by rivers.

____ 3） There is no way to stop soil erosion.

____ 4） Soil is the bottom layer of the Earth's surface.

____ 5） There are dead plants in soil.

III. What's the word? Using the clues, write the correct words from the reading.

1） This includes dead plants, broken rock, air, water, and animal waste: h _ _ _ _

2） This is at the top: s _ _ _ _ _ _

3） These are very small pieces: p _ _ _ _ _ _ _ _

4） This means slowly, not quickly: g _ _ _ _ _ _ _ _

5） This is when trees are cut down: l _ _ _ _ _