�Cause and Effect��Earth Materials ─ Grade 2�Hook ─ Lesson 1�
1
Have you ever wondered where soil comes from?
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cause
The sun heats up�the rock
effect
The rock cracks
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Plants grow�in the�cracks
Pieces of the rock�are pushed further apart
cause
effect
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Water�gets�in the cracked rock
The rocks break�into small pieces
effect
cause
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The rocks in the�river rub against each other
Tiny particles are formed and fall to the bottom
cause
effect
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Soil is made up of tiny pieces of rock that have broken up. It is also made of pieces of plants and even tiny parts of animals.