Given scientific fact as input, generate the question from this fact such that it can be answered from the input.
--------
Question: Destructive interference in waves occurs two troughs what things overlap.

Answer: Destructive interference in waves occurs when what things overlap?


Question: The core of a star collapses during a supernova, forming a neutron star.

Answer: The core of a star collapses during what event, forming a neutron star?


Question: The cell sap is the liquid inside the central vacuole.

Answer:
What is the liquid inside the central vacuole called?