long-established是什么意思？

　　long-established可直译为“长期建立起来的”.　　例句：　　

1、as the island does have a long established gay scene this clearly suggests mykonos is both.　　由于岛上也有一个历史悠久的同性恋场景这清楚地表明米科诺斯兼而有之。　　

2、catholic college of education sydney has a long established tradition in preparing teachers for the catholic school system.　　悉尼天主教教育学院在为天主教学校培养师资方面有悠久的传统。　　

3、this hypothesis fits well with the long established cause of the most common form of natural monozygotic twins.　　此假设与长期以来自然受孕的单卵双胞胎最常见的原因非常吻合。