How did the natural environment impact
the routes used by Marco Polo?

Suppose that you are in a room with 3 doors and a crack in the ceiling for light. that is all. the doors each have a sign on them that says what there is behind them. door #1. a pool of corrosive acid. door #2. a crocodile that hasn't eaten in 8 months. door #3. a solar "oven". a giant lens that focuses all the sunlight at the entrance of the door. you must choose a door, which door do you choose?

Which style of polyphony uses a borrowed chant and arranges several new melodies and texts above and unrelated to the chant?

How does the character of the fourth movement compare with the first three? consider such factors as tempo, texture, rhythmic character, and melodic themes.