Denmark, Sweden
Denmark, Sweden, Finland, Germany, Poland, Lithuania, Latvia and Estonia all border the Baltic Sea..
North Sea and Baltic Sea
Denmark, Sweden, Finland. Also Germany and Poland.
Latvia and Russia
the north sea the north sea
Finland and Norway
Finland and Norway
The cis nations are the Commonwealth of Independent States Nations. The Aral Sea and the White Sea are the two seas that are completely surrounded by the CIS nations.
Sweden and Poland
The general name would be "the Baltic Sea". Ps. The Soviet Union doesn't exist anymore;)
The Gulf of Bothnia (which is the northernmost arm of the Baltic Sea) on the west, and the Gulf of Finland (which is the easternmost arm of the Baltic Sea) on the South. (NB: Bothnia in the Baltic is not to be confused with Bosnia in the Balkans!) There is no border with the Berents Sea in the Arctic, because northern Finland is now landlocked by northern Norway and north western Russia. There is also no border with Lake Ladoga as that is entirely within the Republic of Karelia in Russia today. Finland used to border these two bodies of water, but after World War II, both Pechenga/Petsamo to the north and the Karelia region in the south east were ceded to the USSR.