Write a correct answer to the given question based on its associated fact. Make sure that your answer is contained in the associated fact. Don't be creative and introduce any new word that is not mentioned in the associated fact! Remember that the associated fact has been rearranged to form the question. So, the correct answer words must lie within the associated fact. The correct answer can be a word, phrase, or even a sentence.

Fact: Plants are essential for cellular respiration for all aerobic organisms. 
Question: What is essential for cellular respiration for all aerobic organisms.?
Plants.

Fact: Evolution occurs by a sorting mechanism process. 
Question: How does evolution occur?
A sorting mechanism process.

Fact: paper can change shape from smooth into compacted by physical force. 
Question: what can change shape from smooth into compacted by physical force?

paper.