Coastlines, however, do not indicate the actual boundaries of the continents. Continents are defined
by their continental shelves. A continental shelf is a gently sloping area that extends outward from
the beach far into the ocean. A continental shelf is part of the ocean, but also part of the continent.
To geographers, continents are also culturally distinct. The continents of Europe and Asia, for
example, are actually part of a single, enormous piece of land called Eurasia. But linguistically and
ethnically, the areas of Asia and Europe are distinct. Because of this, most geographers divide
Eurasia into Europe and Asia. An imaginary line, running from the northern Ural Mountains in
Russia south to the Caspian and Black Seas, separates Europe, to the west, from Asia, to the east.

2. What two distinctions does this article say characterizes the differences between regions of
Asia and Europe?