input question: -  Water evaporates from the ground up to the sky - Water droplets are in clouds - The air gets cold - Water droplets turn into ice crystals  What might be the last step of the process????
output answer: Ice crystals in clouds stick together and become snowflakes.
-  Food is put into mouth - Food is chewed and mixed with saliva (spit) - Food travels down the esophagus (throat) - Food travels into the stomach - Acid in the stomach breaks the food down further - Food travels into the small intestine - Nutrients from food are absorbed into the blood stream - Food travels into the large intestine - Most of the remaining material is now waste  What might be the last step of the process?
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Answer: The waste is eventually removed from the body.
Q: -  A forest fire starts - The trees and plants burn - The animals lose their homes - If the animals can not escape, they may die from smoke inhalation - The plants that provide food are gone  What might be the last step of the process?
A: The animals have little to eat
Question: -  A sperm meets an egg in the uterus of a woman - The sperm implants itself into the egg - The sperm and egg form a zygote on the wall of the uterus - The fetus grows and develops - The woman gives birth to a baby - The baby is raised by parents until it is able to take care of itself - The person goes out into the world and finds a job - The person meets other people and has a life - The person gets a career, and gets married  What might be the last step of the process?
Answer: The person retires and eventually passes away
[Q]: -  Carbon dioxide from the air passes through small pores (holes) in the leaves - These pores are called stomata - Water is absorbed by the roots - It passes through vessels in the stem on its way to the leaves  What might be the last step of the process?
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[A]: Sunlight is absorbed by a green chemical in the leaves.
Problem: Given the question: -  Air is brought in through the mouth - Passes through the lungs - And into the bronchial tissue - The carbon dioxide is removed  What might be the last step of the process?
++++++++++++++++++++++++++++++++
The answer is:

The lungs bring the oxygen to the rest of the body.