Why are borders important to nations?

Which is the best example of a primary source ducument useful in the study of history ?

An educatethe yuan dynasty was responsible for which of the following: i. improving the road system ii. increasing sea trade with india and south east asia. iii. extending the canal system iv. brutal warfare and ruthless killing of people in order to take over china. a. i & iii c. iv only b. ii only d. all of the above member of the government

Describe the events that preceded and led to the partition of india. what were the effects of partition on india and pakistan?