1917: Russia stopped fighting in WW1 and the Russian Empire was dissolved and replaced by the USSR.
1945: Russia/USSR had stopped fighting in WW2 after they succsessfully deafeated the Nazis.
1985: Dont know
1991: USSR dissolved
The Russia was significant in the years 1917, 1945, 1985, and 1991, because in 1917 Russian Empire was abolished, in 1945, Nazi defeated in WWII.
In 1917, the Russian Empire was abolished and replaced by the USSR after Russia quit fighting in WW1.
In 1945, after defeating the Nazis in World War II, Russia/USSR ceased fighting.
In 1985, With the foundation of the Commonwealth of Independent States, the Soviet Union came to an end. Mikhail Gorbachev was the president of the Soviet Union at the time of its disintegration.
He was only in this role for a little over a year, yet he was the Soviet Union's leader from March 11, 1985 to March 11, 1986.
In 1991, the Union of Soviet Socialist Republics was dissolved.
Learn more about Russia, refer to:
https://brainly.com/question/9695945
#SPJ2
