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

[Q]: Destructive interference in waves occurs two troughs what things overlap.
[A]: Destructive interference in waves occurs when what things overlap?


[Q]: Negative growth rate results when birth rates fall even lower than death rates.
[A]: What results when birth rates fall even lower than death rates?


[Q]: Group 13 of the periodic table is also called the the boron group.
[A]:
Group 13 of the periodic table is also called what?