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.
Tin (Sn) is one of the few metals which has been used and traded by humans for more than 5000 years. One of its oldest uses is in combination with copper to make bronze. Copper was first coated with tin in the first century AD and tin-plated iron was manufactured in the 16th century.