What are 'The Four Basics of the American Art of a Humorous Story' according to Mark Twain?

Ok I am doing correspondence schooling for this year and this was one of my questions for a test this is what my book had to say about "The Four Basics to the American Art of the humorous story." It can be found in Mark Twain's "How To Tell A Story." 1) "To string incongruities and absurdities together in a wandering and sometimes purposless way, and seem innocently unaware that they are absurdities" >Twain also states here that that is the basis of American Art< 2)"The slurring of the point" 3) "The dropping of a studied remark apparently without knowing it, as if one were thinking aloud" 4) "The Pause" >Mark Twain also emphazises that this is the most important of the four< *The reason he chose to mention the pause at the end is because he felt that people best remember the last thing they read... and since this is the most important he chose to put it last. I hope this could be of help to you