What are the duties of the various congressional leaders? in civics book?

The Speaker of the House is the presiding officer that keeps order in the House. He is the leader of the majority party and is responsible to appoint members to certain committiees. He is the next in line to become president should the president and vice president not be able to fullfill their duties. The majority leader helps the speaker. He is the main spokes person for his party and he tries to convince members to vote with the party leaders. The minority leader determines how his part will feel about the majority leaders programs.