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

Example Input: The heterotroph eats only or mainly plants.
Example Output: The heterotroph eats only or mainly what?

Example Input: Protists are thought to be the oldest eukaryotes.
Example Output: What is thought to be the oldest eukaryotes?

Example Input: Caffeine and alcohol are two examples of a psychoactive.
Example Output:
Caffeine and alcohol are two examples of what type of drug?