Answer:
The answer is: Many are associated in pairs, trios, groups or clusters, and their distribution in filamentary structures.
Explanation:
Galaxies rarely appear isolated and their distribution in the Universe is not uniform. Many are associated in pairs, trios, groups of some tens or clusters of up to a few thousand. These groups are held together by gravitation.
The large-scale distribution of galaxies seems to indicate that they are concentrated along large filamentary structures.
The answer is: Many are associated in pairs, trios, groups or clusters, and their distribution in filamentary structures.
