This is the 275th most frequent Chinese word.
那些
"Those."
In this sentence, '那些' means 'those' and is used to specify particular items.
那些书是我的。
Those books are mine.
'那些' specifies a time period in the past, indicating 'those years'.
那些年来，他一直努力工作。
During those years, he worked diligently.
'那些' is used to specify particular explanations being referenced as 'those'.