The Tigris provided fresh water in order to grow crops they created things called leeves that transport water to supply it. The eurphrates did the exact same thing they provided water for the crops. Hope this answered your question.
The First and Second Estates, comprised almost unanimously of the nobility, could always outvote the Third Estate. Since 1614, the economic power of the Third Estate had increased dramatically; in 1788, the popular call was to double the number of representatives from the Third Estate so that they'd have equal voting power in comparison with the other two estates. They wanted equal rights to vote and have representation in their government.
C, Niagara Falls is around Canada