Questions

Therefore the answer for What travels around the world but stays in one spot is STAMP or any other thing that acts as a stamp does.

Ex. the letter in the envelope etc...

Since, Several things have the possibility, but the word travel evokes that it would move. 

Labyrinth which is part of the ear is the main organ of balance in the human body.

Cast iron is a group of iron-carbon alloys with a carbon content greater than 2% and is a brittle material.

Its usefulness derives from its relatively low melting temperature.

The ancient goal of astrology was to predict human events.

"The reason for playing softly" is not a motive. Motives are the building blocks for large forms composed during the common practice period and, for some, beyond. Composers who used motives would include Beethoven, Mozart, Schubert, Mendelssohn and Brahms.