In a time before railroads and highways, the Great Lakes and St. Lawrence River served as the primary transportation system. Many of North America's largest cities were established along the waterway as commerce flourished between their ports. Today, Great Lakes-Seaway shipping is equally important.
I would say most likely different tribes
Answer:
it turns into
Sulfur dioxide
Explanation:
Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air.
Answer: c) The formation of the ice age glaciers occurred about 21,000 years ago.
Explanation:
The last glacial period occurred in the period between 115,000 - 11,700 years in the past with the recent glacial period called Quaternary glaciation. Though some call this period the last ice age, it is a wrong definition because ice age is defined by year-long ice which still persists in the Antarctica and Greenland. The last glaciation that occurred 21,000 years in the past, is the last glaciation on Rocky Mountain.
It occurred in the period 31,000 - 10,000 years and between 23,500 - 21,000, it was at its highest. The glaciation was not made of the giant ice sheet but was made of mountain glaciers known as Cordilleran Ice Sheets. These sheets produced Lake Missoula which late caused Missoula flooding.
OK so basically in the middle ages Spain was ruled by the Muslim moors <span />