TASK DEFINITION: Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
PROBLEM: A(n) gastropods is noted for having its eyes at the tips of stalks or tentacles that emerge from its head.

SOLUTION: What type of creature is noted for having its eyes at the tips of stalks or tentacles that emerge from its head?

PROBLEM: The pressure of a sample of gas is measured with an open-end manometer.

SOLUTION: The pressure of a sample of gas is measured with an open-end what?

PROBLEM: When an oxidation number of an atom is decreased in the course of a redox reaction, that atom is being reduced.

SOLUTION:
When an oxidation number of an atom is decreased in the course of a redox reaction, that atom is being what?