To protest segregation, African-Americans founded national organizations, among which was the National Association for the Advancement of Colored People (NAACP) which successfully argued that segregation facilities, especially schools, were unequal before the Supreme Court.
among which 이 다음에 완전한 절이 와야하는거 아닌가요?? among which 가 전치사+관계대명사니까...
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