What is important about the progressive dates on the map?

Compare and contrast the first and second battles of panipat.

One drawback of voluntary trade is that it a. requires two groups to use a common language b. can make one group dependent upon another for necessary goods c. doesn't occur unless there is a shortage of goods for at least one group d. forces groups to rely on themselves to produce all the goods they need

What is the level of government responsible for things like police and fire, protection, and is led by a mayor or council?