It is the use of horses for transportation and warfare that explains why Inner Eurasian pastoralism proved the most mobile and the most militaristic of all major forms of pastoralism.
B. It was based primarily on horses rather than on other animals.
C. It borrowed and improved upon European ideas for mobility and warfare.
C 选项加了东西,另外这是一个强调句
Pastoralist communities do not have social classes in the usual sense because they value spiritual attainment over material wealth.
这里加了别的东西