Q: - A stream or river must occur - Through erosion, the stream cuts into the soil and bedrock - Through continuous erosion, a deep gash is cut through - After many years the river may dry up What might be the last step of the process?
A: A dry ravine is left

Q: - Dead organic material accumulates on the bottom of oceans, riverbeds or swamps, mixing with mud and sand - Over time, more sediment piles on top - The resulting heat and pressure transforms the organic layer into a dark and waxy substance known as kerogen - Left alone, the kerogen molecules eventually crack - The molecules break up into shorter and lighter molecules composed almost solely of carbon and hydrogen atoms What might be the last step of the process?
A: It will turn into either petroleum or natural gas

Q: - There are places inside Earth where rock will melt - Melted rock inside the Earth is also called molten rock, or magma - Magma moves up through Earth's crust, but it does not always reach the surface - When magma erupts onto Earth's surface, it is known as lava - As lava flows from volcanoes it starts to cool What might be the last step of the process?
A: Minerals form when magma and lava cool

Q: - Humans are born as babies - Babies become infants - Infants become children - Children learn skills - Children become teenagers - Teenagers undergo puberty - Teenagers become adults - Adults have children - Adults become elderly What might be the last step of the process?
A:
Elderly humans die.