Q: In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.
Question: The main functions of epithelia are protection from the environment, coverage, secretion and excretion, absorption, and this? Answer: filtration
A:
The main functions of epithelia are protection from the environment, coverage, secretion and excretion, absorption, and filtration.