What are the statements? we need more information in order to answer your question :/
Answer:
Your answer will be (a) polder.
A wall stands using gravity. It is constantly being pulled down. Many also place them in ways that they dig into the ground, and almost make a socket just for the wall to be placed, using the land that is there. More and more walls are placed and eventually, they make flooring and a roof.
Hope that helped!
Answer:
a system of choosing areas to be developed for particular purposes, such as houses or shops, when planning a town
It is Important because an unusual occurrence in the realm of international relation