这个小岛由几个富商家族统治，形成了典型的寡头政治体系。

The small island is governed by a few wealthy families, forming a typical ___oligarchic system.

那个国家的经济被少数富豪家族以寡头政治的方式控制着。

The economy of that country is controlled in an ___oligarchic manner by a few wealthy families.