This is the 3692nd most frequent Chinese word.
若干
"若干" means "certain amount" or "several."
In this sentence, '若干' signifies 'several' or 'many', indicating an unspecific quantity of years.
若干年来，他一直致力于环境保护。
For several years, he has been committed to environmental protection.
Here, '若干' implies 'several', referring to an unspecific quantity of suggestions.
会议中提出了若干建设性的建议。
Several constructive suggestions were proposed during the meeting.
In this example, '若干' stands for 'some' or 'certain', representing an unspecified amount of details.