After the persian war, what did sparta, athens, and other greek communities collect to ward off future external attacks?
a slaves
b corn and other grains
c money
d resources for building walls

D

Explanation:

After the Persian War, Sparta, Athens, and other Greek communities collected resources for building walls to ward off future external attacks. ... Building walls, however, had little effect on attacks that were launched by sea, and they were many.

D

Explanation:

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.