David Tribble is with the Washington urban debate league, a nonprofit organization that promotes class debates.

David Tribble与华盛顿城市辩论联盟合作，这是一个鼓励班级辩论的非营利组织。

The former Presdient of the national urban league rose to prominence as a civil rights activist.

这位美国城市联盟的前主席作为民权运动活动家而声名显赫。