Generate a topic word for the given sentence. A topic word is usually the name of a person, place, animal, concept or object the sentence is focusing on.

[Q]: the somatic nervous system (sns) is part of the peripheral nervous system.
[A]: somatic nervous system

[Q]: ammonium carbonate, also known as baker's ammonia or sal volatile, is a chemical compound.
[A]: ammonium carbonate

[Q]: the matariki network of universities (mnu) is an international group of universities created in 2010.
[A]:
matariki network of universities