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

Example Input: Digestion begins in the gastrovascular cavity.
Example Output: Where does digestion begin?

Example Input: Lipids are available to the body from three sources.
Example Output: Lipids are available to the body from how many sources?

Example Input: The water cycle involves movement of water between air and land.
Example Output:
The water cycle involves movement of water between air and what?