oligopoly

An oligopoly of four supermarket chains controls over seventy percent of the grocery market.由四家连锁超市组成的寡头垄断控制着杂货市场百分之七十以上的份额。

The oligopoly reduced competition and allowed firms to maintain artificially high prices.寡头垄断减少了竞争，使企业得以维持人为的高价。