Rome began to lose territory after the pax romana because its military relied on untrained soldiers. expansive borders faced constant attack. stock of weapons began to run out. emperors lost control of the population.

other sources of text

explanation:

this can be magazines, news reports, scholarly articles, textbooks, research papers etc.

no statements but ok.

the statement that best describes the idea of manifest destiny that was used in the 19th century would be that "it was fate that the united states would continue to  expand westward," since people thought the us was "destined" to do so.