Given scientific fact as input, generate the question from this fact such that it can be answered from the input.

Input: Consider Input: Matter that mechanical wave energy can only travel through is medium.

Output: What is the name of matter that mechanical wave energy can only travel through?


Input: Consider Input: Environmental changes is most responsible for the extinction of most species of plants and animals that have lived on earth.

Output: What process is most responsible for the extinction of most species of plants and animals that have lived on Earth?


Input: Consider Input: Potential energy type of energy is possessed by autumn leaves before they fall.
Output: What type of energy is possessed by autumn leaves before they fall?