the three main groups are that you gey(:
three groups of amphibian
The three main groups in science are chemistry,biology and physics.
Three groups of cnidarians are 1. nematocyst 2. cnidocytes 3. gastrozooids
To narrow it down to three groups, it would be strings, winds, and percussion.
The three groups of Orca are Transient, Resident and Offshore. See link below..
Three groups of seedless vascular plants: Ferns, Mosses, Liverworts.
The three groups are bizarre delusions, hallucinations, and a disordered or incoherent thought pattern
Scottish, British (not Scottish), and Polish are the top three ethnic groups in Scotland.
You can make three different groups of three out of nine. 9/3=3
Religious groups, advocacy groups, and the media.
It has three main groups.