The statement A small portion of Russia is completely separated from the main part of the country, and shares a border with Lithuania is TRUE. Lituania is just connected with Poland even if was separated in the part of Russia, but it still shares border with Lithuania.
The Kaliningrad Oblast<span>, which shares a border with Lithuania (on its northers and eastern coasts) and Poland (on its southern coast), is an exclave of the </span>Russian Federation, even though it is geographically separated from the main part of Russia.