Estonia, Latvia and Lithuania
There are three countries in the region known as the Baltic States. They are Estonia, Latvia, and Lithuania. However, the Baltic Sea borders many more countries, such as Finland, Russia, Sweden and Poland.
Estonia, Latvia and Lithuania
Russia has access to the Baltic Sea - in the Russian exclave "Kaliningrad Oblast" there is an important war harbour. Also, Russia has access to the Eastern part of the Gulf of Finland (part of the Baltic Sea), Sankt-Petersburg is actually on the Baltic coast. What was meant in the question were perhaps "Three Baltic States" - Lithuania, Latvia and Estonia (actually, Lithuania doesn't share a border with Russia). Or maybe Latvia, Estonia and Finland?
Sweden, Finland and Russia.
The Baltic states are the three countries east of the Baltic sea: Estonia, Latvia, and Lithuania. These three countries gained their indepedence from Russia in the aftermath of WWI.
It is the Baltic Sea. Note that the Baltic region comprises all the above countries plus Denmark, Germany and Russia (9 countries in total), while the Baltic countries are only three: Estonia, Latvia and Lithuania.
The three Baltic republics are Latvia, Lithuania, and Estonia
There are three countries that share a border with Poland and the Baltic Sea. Germany, Russia, and Lithuania all share borders with Poland.
The three Baltic republics are called the Baltic states, Baltics, Baltic nations, or Baltic countries. The countries include Lithuania, Latvia, Estonia.
The three Baltic states are Estonia, Latvia, and Lithuania.
Estonia, Latvia, and Lithuania are the countries in the European Union which border the Baltic Sea. These three countries are the Baltic States.