The Chinese notion of "barbarian" was anyone who wasn't Chinese. What characteristics of the Xiongnu made them seem barbarian to chao cou ?

the answer would be c

c, because the american revolution was from 1765 to 1783.

the  seven  days  battles  were  a series of seven battles over seven  days from june 25 to july 1, 1862, near richmond, virginia,  during  the american civil war. the  seven  days ended with mcclellan's army in relative safety next to the james river, having suffered almost 16,000 casualtiesduring  the retreat.