B7

A.
1) Advantages in a federal system of government are that it decentralizes countries that are high in population and size and that depending on a countries diversity, the people need to be closer to policymakers so they can all voice their opinion.
2) A unitary government is one that all the power lies in the central government. Life would be better under a unitary government system because everyone would have the same laws to obey and no one would get confused about the laws and regulations when crossing intrastate/city boundaries (like one might where speed limits and other driving laws are different from state to state in the U.S.).
B.
1) One enumerated power given to the National government is the power to coin money. This is a good thing because otherwise each state could have their own currency and traveling from state to state with different currencies would be confusing and annoying.
2) One power given to the States is marriage rights. It is legal for one state to allow same sax marriages and for another to make it illegal. This best belongs to the states because if a state is more lenient to not allowing same-sex marriages the people can vote for it to be illegal or if they do want it then the state legislatures will recognize it.
3) One concurrent power is the power to build and maintain roads. This best resides as a concurrent power because citizens of the U.S. use roads across states.