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

Ex Input:
Opaque is the term for matter that does not let any light pass through.

Ex Output:
What is the term for matter that does not let any light pass through?


Ex Input:
Volvox sphere has a distinct front and back end.

Ex Output:
What has a distinct front and back end?


Ex Input:
Substances produced by a reaction are known as products.

Ex Output:

Substances produced by a reaction are known as?