The plural of frontier is frontiers.
The word frontier is a noun. The plural is frontiers. Frontier can also be used as an adjective.
There is no plural noun. The two nouns in the sentnece are life and family. The word family is a singular noun, the plural form is families. The word life is a singular noun, the plural form is lives. Actually, using either or both plurals (lives, families) would not change the meaning of the sentence.
The New Frontier.
the 5 western frontiers are the indian frontier the farming frontier the cattle frontier the mining frontier and the buffalo frontier
Frontier.
The motto of E Frontier is 'e frontier spirit'.
as in battle frontier
what is internal frontier
. . . New Frontier.
A 2002 Nissan Frontier bed will not fit a 2000 Nissan frontier.
frontier opened my miners
you have to beat the frontier brains