What made the Colombian exchange different from previous trade routes?

How does the pyramid of giza include art, science, math, or a need for infrastructure?

In the 1980s, more russians worked to encourage change in the government by a) establishing a new political system. b) rallying for democratic reforms. c) supporting the democratic system. d) resisting gorbachev’s reforms.

Which lake receives up to 9 million visitors each year, covers more than 90,000 acres, and was created by denison dam? a. the grand lake o' the cherokees b. lake thunderbird c. lake eufaula d. lake texoma