‘fall suddenly’ is what it means in historical terms. Hope this can help! :O
What are the options to chose from
The Constance of urban life since the early 1900s has been a relocation of suburbs. Option B is correct.
The increasing population in urban areas pushed many people, specially the wealthy ones to the suburs were they could stay in a most tranquil place far way from the noisy and crowded big cities. So, it became a costum to be commuting to the town.
In 1950 60% on people lived in the central city and 40% livied in the suburbs. By 1980 the percentages reversed with 40% living in the central city and 60% living in the suburbs.
The soviet union led by Gorbachev was no longer willing to intervene in the eastern Europe countries. Back at home strong communist generation of leaders like Tito had already passed away. the soviet masters were also embarking on a series of reforms that were becoming more capitalists.
