Nineteen ninety-one was also the last year for the U.S.S.R., the Union of Soviet Socialist Republics.

1991年也是苏联苏维埃社会主义共和国联盟的最后一年。

Gorbachev became the leader of the Union of Soviet Socialist Republics, or USSR, in March 1985.

戈尔巴乔夫于1985年3月成为苏维埃社会主义共和国联盟（简称苏联）的领导人。

The Union of Soviet Socialist Republics as it was also known came to an end in 1991.

1991年底，苏维埃社会主义共和国联盟宣告结束。

When it existed from 1922 to 1991, the Union of Soviet Socialist Republics was by area the world's largest country.

当它存在与1922年到1991年时，苏维埃社会主义共和国联盟是世界上面积最大的国家。

On December twenty-fifth of that year, Mikhail Gorbachev resigned as president, as the Union of Soviet Socialist Republics came to an end.

同年12月25日，随着苏维埃社会主义共和国联盟解体，戈尔巴乔夫辞去总统职务。