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.

Example Input: Question: Expansion of a gas into a vacuum is irreversible because the external pressure is measurably less than the internal pressure of the gas, and no states of what exist? Answer: equilibrium
Example Output: Expansion of a gas into a vacuum is irreversible because the external pressure is measurably less than the internal pressure of the gas, and no states of equilibrium exist.

Example Input: Question: What type of energy travels through matter in wave form? Answer: sound
Example Output: Sound energy travels through matter in wave form.

Example Input: Question: What type of resource cannot be replaced as easily as it is consumed? Answer: nonrenewable
Example Output:
Nonrenewable resources cannot be replaced as easily as it is consumed.