What evidence shows the spread of Bantu culture throughout Sub-Saharan
Africa?

they were unable to pay their debts

the east coast has nothing to do with the dust bowl, the dust bowl killed a full year's worth of crops in seconds, and with the dust on the land, the land would be worthless.   furthermore the farmers couldn't  get  out of their houses due to the dust so when the bank came to collect money, farmers couldn't  pay it

why was the national assembly formed by the third estate?

the estates-general had not been assembled since 1614, and its deputies drew up long lists of grievances and called for sweeping political and social reforms. the third estate, which had the most representatives, declared itself the national assembly and took an oath to force a new constitution on the king.