The urban middle class is the correct answer :) I hope this help, have a lovely day.
The answer to this question is the second item in the choices which is "where older buildings were built on a thick layer of sediment". We know that seismic vibration is the sound or movement generated from the ground. This happening is unwanted and cannot be controlled. Once this occurs in higher magnitude it would cause great damage to our structure were buildings made of rock collapse.
The collapse of the Soviet Union
<span> factors were responsible for environmental improvements in Eastern Europe during the 1990s</span>
