The Disappearance of the frontier came when

brainliest pl

Explanation:

1890

In 1890, the Census Bureau announced the end of the frontier, meaning there was no longer a discernible frontier line in the west, nor any large tracts of land yet unbroken by settlement. This news had a terrific psychological impact on many Americans. For the first time in history, America was without a frontier.

the correct answer is "c: merchants" and "e. soldiers".

the song dynasty was known as the first government in the world to introduce paper currency. it was also the first chinese government which established a permanent standing navy. finally, the first compass was introduced during this period of government.

all of these innovations heavily affected commerce in a positive way. printed money dynamize commerce within the borders of the empire due to an easier way to quantify value during the trade. the introduction of the compass trade routes to be faster. finally, the introduction of a standing navy regulate trade routes.

regarding military affairs, gunpowder was created during this period. this was a tremendous improvement that was widely utilized by the military in order to innovate in the manufacturing of weapons.