What are the advantages of a bicameral structure of congress proposed by the constitution as opposed to the unicameral proposed by the article of confederation

The tea party movement is a. an official third party that challenges both democrats and republicans in national elections. b. an organized challenge to incumbents in the republican party by the most conservative wing of the republican party. c. an organized challenge to incumbents in the democratic party by the most liberal wing of the democratic party. d. an offspring of the green party that runs for state and local office in many midwestern states. e. the now defunct party that gave way to the republican party at the end of the “second party system.”

Why did lincoln inform the confederacy that he would not e sending troops or weapons as food supplies were sent to fort sumter?

Why are the majority of the world's economies mixed? what may happen to the "pure" types of economies (traditional, socialist/command, market capitalist) when they incorporate elements from other economic models?