Complex sentence: For decades following the Chinese Revolution of 1949, marriages between foreigners and Chinese people were unusual, and perhaps non-existing during the Cultural Revolution, but they were never explicitly banned or judged unacceptable on a racial basis.
Split into simpler sentences: For decades following the Chinese Revolution of 1949, marriages between foreigners and Chinese people were unusual, and perhaps non-existing during the Cultural Revolution. But they were never explicitly banned or judged unacceptable on a racial basis.