“巩固的”的英语？

那家地位巩固的公司倒闭了,造成6000个职位丧失.The well - established firm closed down with the loss of 6000 jobs.演员要得到巩固的地位不容易.It isn't easy to get a foothold as an actor.教育上的联系造成最巩固的连结.Educational relations make the strongest tie....