input question: -  The water freezes and thaws - Cracks form in the rocks - Cracks also form when rocks heat up - The rocks slowly break down.  What might be the first step of the process????
output answer: Water seeps into rocks

input question: -  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 - It will turn into either petroleum or natural gas -   What might be the first step of the process????
output answer: Dead organic material accumulates on the bottom of oceans, riverbeds or swamps, mixing with mud and sand

input question: -  The liver uses chemicals and proteins to treat the blood - The blood is cleaned - Energy is produced - The blood leaves the liver cleaned.  What might be the first step of the process????
output answer: Blood is sent to the liver

input question: -  The sound travels in waves, as sound does - The sound 'bounces' off of a nearby object - The sound wave returns to the bat - The bat hears the echoed sound - Folds in the bat's ear and adaptations in the bat's brain enable it to determine the size, shape, and position of the other object via the properties of the returned sound waves - Other animals use echolocation in generally similar ways -   What might be the first step of the process????
output answer:
Bats and other animals produce a high-pitched tone