How does twain's vivid description of the letter affect the climax of the story?

Label the different parts of the stage. downstage stage left audience stage right upstage

The greatest gift the sumerians gave the world was the invention of writing. the sumerians were wealthy people. they needed some way to keep track of what they owned. they began drawing pictures. they used a reed as a pen. they drew on soft pieces of clay. the soft clay was then dried in the sun. the tablet became a permanent record. later, the sumerian drawings changed into wedge-shaped symbols. this kind of writing is called cuneiform. by putting symbols together, the sumerians could write entire sentences.

In the poem i felt a funeral, in my brain, what rhyme scheme does the poet use and how does it contribute to the poem?