The serves as a border between the northeastern united states and canada.
a.
mackenzie river
b.
mississippi river
c.
st. lawrence river
d.
rio grande

The St. Lawrence River serves as a border between the Northeastern United States and Canada. The St. Lawrence River is located in the middle latitude of North America. It is a large river that flows north-easterly direction. It serves as an international boundary between Canada, Ontario and US.

in the 1950s, country music came into its own before rock-n-roll took off in the 60s while jazz and classical music continued to innovate

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explanation:

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