They describe sudden changes in Earth's surface due to volcanic eruptions, landslides, earthquakes and flooding and compare those with the slow changes due to weathering and erosion.
(They; describe; sudden changes in Earth's surface due to volcanic eruptions, landslides, earthquakes and flooding) (They; compare; those with the slow changes due to weathering and erosion)
They They
describe compare
sudden changes in Earth's surface due to volcanic eruptions, landslides, earthquakes and flooding
those with the slow changes due to weathering and erosion