How did the spanis impact iran

Silver is the answer i thinkhope it helds

In 911, a group of vikings lead by rollo besieged paris and chartres. after a victory near chartres on 26 august, charles decided to negotiate with rollo. the talks were led by hervé, the archbishop of reims. this resulted in the treaty of saint-clair-sur-epte, which granted rollo and his soldiers all the land between the river epte and the sea. it also granted him brittany, "for his livelihood". at the time, brittany was an independent land which france had not been able to conquer. in exchange, rollo promised the king his loyalty and military assistance when needed. also rollo also agreed to be baptised and to marry gisela, the king's daughter. the territory given rollo is about the same as upper normandy. this would grow to become normandy under rollo's descendants. - wikepedia

The following passage describes an example of __negative externality in the 1980s, manufacturing power plants in the midwest burned coal with high sulfur content, which when released as smoke, mixed with moisture in the atmosphere to create an acid that blew into canada and new england. the acid fell to the earth in the form of rain, killing fish and causing deforestation and building deterioration.