In contrast to America, which of the following were characteristics of the Soviet Union? one-party system Judeo-Christian Communist republic multi-party system atheist

In contrast to America, the characteristics of the Soviet Union was that it was a "Communist republic," since this was during the cold war--and a massive fight between democracy and communism existed. 

The main thing that contrasted the United States of America and the Soviet Union was that the latter was a one-party system country coupled with their communist republic characteristics. Both of these things strongly characterized the difference between the American and the Soviet Union countries.