Answer:
A coastal plain is a flat, low-lying piece of land next to an ocean. They are far away from mountains.
New Zealand's main source of energy is hydroelectric power
I would say that the Rocky Mts were the youngest of all these mountain ranges as they were created between 80-55 million years ago during the Laramide Orogeny and also they are generally much taller than the other mountain ranges mentioned here which is a characteristic of young mountain ranges and their features are sharper as they haven't been eroded the way most of these others have so have been subject to erosion for less time than the others.
The energy supply we have so technology is advancing as the population increases, we need to burn fossil fuels for energy for new technology, causing an increase in greenhouse gases, such as carbon dioxide to be emitted