Which two countries built the st. lawrence waterway? answer in the best way!

St. Lawrence Seaway, continuous navigable deep waterway project from the Atlantic Ocean to the Great Lakes, undertaken jointly by Canada and the United States and completed in 1959. The St. Lawrence Seaway opened North America's industrial and agricultural heartlands to deep-draft ocean vessels.

yes

explanation:

explanation:

the addition to geographic boundaries that might have  kept the people of the huang river civilization from traveling to far distance region is that they had learned about the other river valley civilizations but feared contact would bring invasion.

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