The short answer: 20 (composite score) is the national ACT average. About half of students score above that, and half of students score below. The top 25% of ACT takers score about 24 or more, so if your score is above 24, that's excellent.
1 SavinâNorov machine gun. 2  Space Network, a NASA relay satellite system. 3  Sthene, an obsolete unit of force or thrust in the metre-tonne-second system of units. 4  Substantia nigra, a brain structure. 5  Supernova, a stellar explosion, in astronomy and cosmology.  Tin, a metallic element with chemical symbol Sn.
Diffen âº Science âº Biology âº Anatomy. The parasympathetic nervous system (PNS) controls homeostasis and the body at rest and is responsible for the body's rest and digest function. The sympathetic nervous system (SNS) controls the body's responses to a perceived threat and is responsible for the fight or flight response.