What exists when 2 places have a comparative advantage in what the other place wants?

What is found within a ranger tower overlooking a drained lake

On nights when we see the new moon phase, what side of the moon are we seeing?

In wegener’s evidence for continental drift, continents were proposed to fit together, such as the east coast of south america with the west coast of europe. east coast of africa. west coast of greenland. lower west coast of africa.