HELPPP somebody please answer 1 and 2 and 3 please no links

2. what was the dred scott decision about? what do we learn from this supreme court case?

Ineed asap! ! what is the name of the system in which each branch of the u. s government can limit the actions of the other branches? a. perpetual union b. division of powers c. cooperative federalism d. checks and balances

The quote below is an excerpt from the charter of the united nations: "the purposes of the united nations are: to maintain international peace and security, and to that end: to take effective collective measures for the prevention and removal of threats to the peace, and for the suppression of acts of aggression or other breaches of the peace, and to bring about by peaceful means, and in conformity with the principles of justice and international law, adjustment or settlement of international disputes or situations which might lead to a breach of the peace . " source:this section implies that the united nations is prepared to do what to keep world peace?