Answer:
its basically where the branches of government check to make sure that no branch is more powerful then the other, an example is that the president can veto a bill but 2/3 vote in congress can override it, another example is that the house of representatives has the power of impeachment but the senate has power to try any impeachment
also the answer will be marked wrong when you look at the score but thats because the teacher has to actually read what you put