Questions

Geysers are fountains of hot water and superheated steam that erupts with an explosion whereas hotsprings or thermal springs are found where water sinks deep enough the surface to be heated up by the interior forces and it comes out without any explosion. Iceland and New Zealand are the other countries having geysers while hot springs are relatively common.

Nucleic acids are polymers of individual nucleotide monomers.

Each nucleotide is composed of three parts:

a 5-carbon sugar,

a phosphate group, and

a nitrogenous base.

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. 

When a running car stops suddenly, the passengers tends to lean forward because of Inertia of motion.

A living community and its environment is what an ecosystem is.

The one word substitution for Of outstanding significance is monumental which has a meaning of great in importance, in size or any such characteristic.