The company had monopolized the photography market for so many decades that they didn't worry about competition from other companies.这家公司垄断摄影市场几十年，他们不担心来自其他公司的竞争。It would take many decades to build up the level of education and sophistication.教养和人情世故需要好几十年的时间来积累。She reigned over her kingdom for many decades.她统治王国长达几十年。The empire held together for many decades.这个帝国数十年没有分裂。