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

Input: Consider Input: A change of season and less food usually cause certain animals to migrate.

Output: Which two environmental changes usually cause certain animals to migrate?


Input: Consider Input: The water in some springs are hot because they're heated by hot magma.

Output: The water in some springs are hot because they're heated by what?


Input: Consider Input: A complex machine is described by: it is made of more than one simple machine.


Output: Which of the following statements best describes a complex machine?