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

Example Input: Compounds with metals and nonmetals sharing electrons are known as ions kinds of compounds.
Example Output: Compounds with metals and nonmetals sharing electrons are known as what kinds of compounds?

Example Input: Oil is the most commonly used source of energy in the world.
Example Output: What is the most commonly used source of energy in the world?

Example Input: The first year after birth is called infancy.
Example Output:
What is first year after birth is called?