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

Input: Consider Input: Ectothermic vertebrates control body temperature to just a limited extent from the outside by changing behavior.

Output: What type of vertebrates control body temperature to just a limited extent from the outside by changing behavior?


Input: Consider Input: Tornadoes can occur in any.

Output: At what time of the year can tornadoes occur?


Input: Consider Input: There are four valves in the heart.


Output: How many valves are in the heart?