I would say B) and D) apply to some of the differences between a Prime Minister and a President and also A). In addition, a Prime Minister is head of the government but may not be head of the state which may be a President in the same country or perhaps a Governor General.
It is the Yangtze River that is not a location of the first civilizations, since the other rivers on the list, especially the Nile and the Tigris and Euphrates were much more able to provide essential crop irrigation.
Answer: cotton was in high demand for cloths and rope
Explanation:
