Quais foram os três principais motivos do início da crise do sistema feudal?
a. as inovações técnicas, as cruzadas e a reabertura do mar mediterrâneo.
b. os conflitos entre clero, nobreza e camponeses.
c. a talha, a corveia e as banalidades.
d. o interesse econômico em algumas regiões do oriente; a necessidade de
exportar a miséria e o crescimento populacional.
e. o interesse econômico, do poder polí

the great wall of china worked as a defense for the feudal states of the zhou dynasty to the north. during the warring states period more walls were put up to defend the borders of the different kingdoms. it was semi successful because despite the wall, the mongols eventually conquered china also the great wall provided protection to the economic development and cultural progress, safeguarded the trading routes such as the silk road, and secured transmission of information and transportation. @jayxboof

president franklin roosevelt supported the tva as part of his first new deal measures approved by congress in 1933. this new agency was designed to control floods, produce electric power, and improve the lives of people living in the tennessee valley. the tva accomplished many of these goals despite problems.