africa的形容词形式怎么写

　　The African elephant is in a desperate plight.

　　非洲象正面临绝境。

　　They flew the flag of the African National Congress.

　　他们挥动着非洲国民大会的`旗帜。

　　Three-quarters of the students are African American.

　　3/4的学生是非洲裔美国人。